Over the course of a weekend, about 100 of Barack Obama’s newest charges gather at the student centre of DePaul University, on Chicago’s North Side. They are the city’s first class of the Obama Foundation Community Leadership Corps, young men and women between the ages of 18 and 25 selected from across the city to be groomed over six months for the type of organising work that launched Obama’s own civic career three decades ago.

One of the recruits’ first tasks during this boot-camp is to identify a problem in their communities they want to fix, so that foundation staff can help them refine strategies. Attendees scrawl their ideas with a marker on butcher paper, and they range from the broad (the elderly population is forgotten) to the specific (Asian-Americans vote at lower rates than whites). Not a single one, however, mentions Donald Trump.

The Community Leadership Corps is among the first tangible products of what could be, given Obama is only 57, a very long post-presidency career. “He feels he’s made the contribution he could make as a public official, and the greatest value he could add is to become a facilitator of the next generation of leaders,” says David Axelrod, Obama’s long-time strategist. The former president had pledged before leaving office to remain largely detached from the political fray. A library and charitable foundation would shape his legacy while Hillary Clinton inherited his policy priorities and stewardship of the Democratic party. It didn’t quite turn out that way, and while a sense of national emergency has risen as Trump’s presidency has progressed, corners of the American left are outraged at his detachment. “Barack Obama, Where Are You?” the cover of New York magazine inquired.

Obama returns to the political fray this autumn by campaigning for select candidates nationwide ahead of November’s midterm elections and he remains the party’s dominant figure even out of the spotlight. In many ways, his presidency is still shaping the Democratic party. Nowhere is that more evident than in Chicago, his de facto hometown. The city houses monuments rising in Obama’s honour, his political movement and a lively business sector that owes its existence to the cutting-edge campaigns he ran. But where do Obama’s values fit in Trump’s America?

When Obama headed to the White House, he moved his family out of their Hyde Park home but his team continued to treat Chicago as his political base. For his re-election, they again picked a headquarters in a high-rise office building in the downtown Loop. When it was time to plan the construction of his library, the secular shrine now granted by right to former presidents, Obama received bids from Honolulu (his birthplace) and New York (where he attended university). But there never seemed much doubt that it would end up in Chicago. After several delays, construction will begin in 2019.

In 2013, anticipating a post-presidential base nearby, Axelrod opened his Institute of Politics at the University of Chicago, where Obama had taught constitutional law. Its goal is to inspire students to follow careers in politics and public service, a path that is increasingly unappealing to many. “My fundamental concern is that they’ll turn in and away from the public square, because there’s such a disincentive for participating, as it is perceived by young people,” Axelrod says, pointing to the general coarseness of US politics. For its first few years, the institute has benefited from its association with the White House, drawing top national figures to campus.

It’s not just Axelrod who’s ended up here. After Trump defeated Obama’s preferred successor, a surprising number of those loyal to the outgoing president – who might have otherwise served Clinton’s administration or benefited from proximity to it – settled in Chicago. At times, it can have the feel of a government-in-exile. The mayor, Rahm Emanuel, was Obama’s first chief of staff. (Emanuel, who has struggled to deal with both high crime rates and abuses by his own police department, wants to run for a third term.) Valerie Jarrett, Obama’s long-time adviser who also built her career in the city, is a senior fellow at the University of Chicago Law School. Two of his former secretaries, Robert Gibbs and Josh Earnest, now head communications for two of Chicago’s largest companies: McDonald’s and United Airlines, respectively.

Yet Obama went quiet. He retreated from public life, devoting himself largely to writing his third memoir. Inasmuch as Trump has chosen to govern as the Anti-Obama, Obama has avoided letting himself become the Anti-Trump. He has refrained from uttering his successor’s name during his few public appearances since leaving office, even when it’s clear who he’s referring to.

In an unusual departure for departing presidents, who tend to stand up their libraries and then develop their other activities, the Obama Foundation started by launching a series of programmes around a mission to “inspire, empower and connect people to change their world”. In addition to the Community Leadership Corps, there are the Obama Foundation Scholars, brought from around the world to the University of Chicago and Columbia University to pursue masters’ degrees in public policy.

The foundation views its theme of “active citizenship,” as CEO David Simas calls it, in assiduously bipartisan terms. Simas, a former White House political director, doesn’t flinch when asked what would happen if applicants sought skills for the purpose of, say, organising gun owners to defend their rights. “There will be conservative young people coming in,” Simas says. “The president’s view of civic leadership transcends party and ideology.”

Obama’s influence also persists in the innovations of his former campaigners, who have gone on to set up consulting firms such as 270 Strategies and Civis Analytics. The Obama Foundation sits in the 270 Strategies portfolio alongside more traditional political clients. That includes several Democrats seeking seats in Congress this year, such as first-time candidate Elissa Slotkin, a former Obama Pentagon official running in a Michigan district. “If the election had gone the other way in 2016, it would be a completely different atmosphere,” says 270 Strategies co-founder Jeremy Bird, “in terms of who’s running, where they’re running and the intensity they bring to it.”

Quantifying that emotion and its electoral impact is one of the year’s big challenges for the number crunchers at Civis, whose analysis supplies top Democratic party organs and super-PACs. They have switched only two seats since 2016 but in every congressional special election nationwide Democratic candidates have run closer races than would be expected based on the local electorate. “This is being driven by Democrats [who are] very enthusiastic to vote,” says David Shor, Civis’s director of political data science. “Our estimates have kept being revised up all year.”

Shor is one of the Civis employees whose lineage tracks to the “Cave”, as the analytics department on Obama’s re-election campaign was known. Their firm now serves a range of clients, from the US arm of UN High Commission on Refugees to the Lyric Opera Company of Chicago, and has grown to about 160 employees.

After Clinton’s failure, in which inaccurate data guided her away from major campaign investments in Wisconsin and Michigan, there has been a backlash against over-dependence on the type of services that Civis offers (Civis didn’t work for Clinton’s campaign). The firm, however, has responded by seeking even more influence in the campaigns it advises.

“After the election, we said, ‘let’s be relevant for decisions that matter,’” says Shor. “You can talk about bread-and-butter issues and it’s often the most effective way to mobilise the base. Voters want to be talked to about concrete, material issues that really shape their lives.”

In August, Obama’s office released a list of 81 candidates he was endorsing for various offices on the November ballot. By waiting until after most states had concluded their nominating contests, he avoided picking sides in internal debates about what exactly a post-Obama Democrat should look like. He is expected to hit the trail for a selection of his candidates before election day, following a map that will be revealing as much for the places Obama goes as where he doesn’t. As much as his popularity has grown out of office, in parts of the country no Democrat benefits by seeing their race reduced to an Obama vs Trump proxy battle.

Such tactical plotting runs through all deliberations at Organizing for Action (OFA), the political operation descended from Obama’s own campaigns. When it was launched in 2013, OFA was handed the Obama volunteer network and the task of trying to advance his agenda. “We had to transition an entire volunteer network that had been a well-oiled machine for electoral-type organising,” says executive director Katie Hogan.

But OFA struggled with Obama in the White House. It was frequently accused of being too successful at raising money from his supporters and not successful enough at mobilising them to pressure Congress. “There is a huge distinction,” says OFA communications director Jesse Lehrich, “between motivating people to elect Barack Obama and trying to convert that into an enduring network of issue activists.”

Impeding Trump’s agenda seems to inspire diehard Democrats to action in a way that promoting Obama’s never did. Activists formed new organising outfits, such as Indivisible and Swing Left, as an alternative to the traditional party organisations, and OFA repositioned itself as a resource for them, with offers to train their staff and volunteers. At the same time, OFA continued to use its “digital megaphone” to amplify the work of more established organisations that specialise in causes such as women’s rights or environmental protection.

But when Trump made a priority of repealing Obama’s health-care law, those new groups lacked the reach or depth to assume a leading role. OFA, however, already had a well-drilled corps of activists nationwide. It was able to quickly populate protests in places such as Alaska and Maine that have never been hotbeds of leftist politics. “It’s not that any other group didn’t have the enthusiasm after 2016, or the know-how,” says Hogan. “But we had the relationships.”

But even as it has become a partner to the resistance, OFA has been reluctant to throw its weight behind futile efforts such as those to stop Trump’s Supreme Court nominee or abolish the Immigration and Customs Enforcement (Ice) agency. OFA’s priorities this autumn includes 23 House districts controlled by Republicans – just enough, if all flipped, to take the majority – and no Senate races, where, most Democrats admit, a change in control looks far-fetched.

If the party does take back the House, OFA seems likely to remain quiet on impeachment, even as activists clamour for it. That innate sense of caution may be the most Obama-like attribute of all. “We’ve always been known as a pragmatic voice,” says Hogan. “I don’t think our tone or our voice has changed at all, I think the environment we’re in has changed.”

Dear Mr Trump,
You might have been obsessed with sleeping with Playboy models and porn stars but it’s going to be suburban women who will get the final word here. Every poll that I’ve seen would suggest you are absolutely haemorrhaging support among this demographic. Many of them may have reluctantly voted for you back in 2016 but much of your presidency has been repellent to them.

You only know one strategy, which is scorched earth. You will try to play the divide on social issues, attack NFL players and play the illegal immigration card. Republicans will, of course, try to paint the Democrats as extreme, radical and alienated from middle America.

Then there’s the question of impeachment. Democrats are downplaying it because it could possibly backfire on them. But there’s no question that a Democratic House would likely begin impeachment proceedings. I think if the Republicans hold the House it will be much Trumpier than it is now, because a lot of the moderates and sceptics will have been defeated. I’m guessing that the day after the election, if the Republicans win, you will be emboldened to fire Mueller or hand out pardons.

What’s most likely to happen is that the Democrats are going to take the House of Representatives (but the Republicans are going to narrowly hold the Senate). This election is going to be a referendum on you, and increasingly I think it’s going to turn on the culture of sleaze and corruption you’re presiding over.

You have been obsessed with your base, which is unmoveable. But this is an election that won’t be decided by people wearing red MAGA hats. Rather, it will be decided by the independent and swing voters who are repelled by the personality, policies and erratic narcissism and dishonesty you embody.

Dear Mr Trump,
The good news for you is that the “Make America Great Again” base has come back quite strongly since it bottomed out a year ago in the wake of the Charlottesville protests, when only 39 per cent of self-identified Trump voters were in strong approval. The latest Morning Consult poll has you back up in the mid-fifties.

The bad news is that the midterm elections aren’t about the support of the base but more about the intensity of the opposition and where public opinion is in swinging independent, persuadable voters. House majorities are won on the seats that don’t lean strongly in one direction or the other, and that makes for a poor reading for the GOP.

Independents are about twice as likely to strongly disapprove of you as they are to strongly approve. In a midterm election cycle, which is a referendum on the president, that’s a huge challenge.

Republicans are leaning heavily into immigration, vilifying Nancy Pelosi and trying to paint every Democratic challenger as out of touch. I think that says a lot about their confidence in their legislative record so far. The question is, are you turning off independents and energising the opposition with that messaging?

What you’re looking at is a 66 per cent chance the Democrats take the House, and a 60 per cent chance of retaining the Senate.

Dear Mr Trump,
You shape the news environment, but the question is whether you have the ability to do so strategically. What you want to talk about are issues of cultural change and ones that produce racial cleavages. You enjoy talking about NFL players protesting police brutality and illegal immigration. In your preferred scenario, those topics would dominate.

Your most successful political message has been claiming credit for the current economic conditions, which are continuing the same job expansion as seen under President Obama. You’ve convinced your voters that the economy, which they used to believe is terrible, is now wonderful.

You’ve split the country along educational lines to a higher degree than ever before. A generation ago, college-educated whites used to be much more Republican than non-college educated whites. But that has reversed. In areas with lots of college-educated white people, Republican candidates are running away from you, and in the areas without them, they’re running towards you.

Your party is certainly eager to talk about impeachment. There’s little likelihood of it happening because two-thirds of the Senate is needed to remove a president, which would require the support of many Republicans, and that’s extremely unlikely. But Republicans think they can energise their base and scare them about what could happen if the Democrats were to control Congress. If Democrats do, I don’t expect a lot of bridges to be built. I would expect them to start to further investigate criminality by your administration. It’s going to deepen divisions, even when it’s hard to imagine them getting any deeper.

Dear Mr Trump,
The American public seems very unsettled with what’s going on in Washington, and almost any time one party looks like it has “captured” Washington, the public uses the midterms to pull back. That’s been the trend throughout the modern era.

The Democrats look to capture between 24 and 35 seats in the House and that’s enough to take it back from the Republicans. Your record in the primaries is very good but there’s an explanation for that beyond the enormous love of your base. The primaries have low voter turnout, so the people who get out and vote are the most active, interested and energised.

But the general election is an uphill battle. If you are to be successful, voters will need to focus on the good economic numbers – low unemployment, good consumer indexes, taxes – rather than making this a referendum on corruption.

What we know almost for certain is that there are 27 purple swing districts, the vast majority held by Republicans, which is why the map is bad for the GOP in the House. The key to this election is suburban, educated female voters. They might have voted for Trump in 2016, but the events of the last couple years, from the Access Hollywood tape to Michael Cohen’s testimony, present them with a challenge. They’re likely to either stay at home or go out, hold their nose and vote Democrat.

Dear Mr Trump,
Your biggest problem is this: while Ronald Reagan assembled a fairly broad base of support – working-class voters who had voted Democrat in the past, Hispanic voters, a majority of female voters – you have alienated huge numbers of people. You have been very effective in throwing red meat to your true believers, but in doing so you and your party have lost huge swathes of the country. You have alienated women, Hispanics and many independent voters. And you have energised the Democratic base to come out against you.

If the Republican party is ever going to regain its status, it will have to bring back into the fold some of the people that your presidency has alienated.

I think it would be wise for you to stay away from a lot of the races being run in this midterm cycle. I’d advise you to stay out of it, to keep your mouth shut and to keep your fingers away from your Twitter account. I think if you don’t, you could end up costing Republican votes.

It will be dangerous for the Democrats to lurch to the left. Americans tend to be centrists. I think Democratic candidates who have fashioned themselves as the resistance, who are running on a distinctly left-wing agenda, may well end up playing into the hands of the Republicans.

Yours is the most incompetent administration I have seen in all my 45 years of being involved in politics in Washington. Yours is the gang that can’t shoot straight.It manages to screw things up virtually every time it tries its hand at something – whether it is the so-called Muslim ban or the policy of separating families from their children at the Mexican border.

But the problem isn’t just with your policies: it’s also with the way you conduct yourself. Republican candidates who want to win should be aware of that. Being more respectful to people who disagree with you, and adopting a kinder, gentler voice, would be one way to win back some of the people you have alienated during your presidency so far.