In 2009, three days into his first term, Barack Obama famously snapped at a congressional Republican leader who questioned whether he had the mandate to pursue an ambitious economic agenda: “Elections have consequences.” That mantra belongs not only to politicians basking in their wins, but also a political class that thrives on the perpetual promise of high-stakes campaigns. Yet this year it’s hard to identify what those consequences could possibly be. It has been decades since Americans have gone to the polls in a national vote with less at stake.

Midterm elections tend to be monumental when they reflect a partisan wave, which can be triggered by two separate dynamics. One is a shift in public opinion triggered by discontent with the party controlling the White House that pulls voters to the opposition. The other is a disparity in turnout among the two party’s bases thanks to one’s coalition being more motivated than the other to vote. When working in sync, these dynamics can reorder power.

In 2006, a Democratic wave was read as a rejection of the Iraq war; a Republican one four years later as disapproval of Obamacare. Yet where once waves had the power to reorder sandcastles, one this year would likely wash over a hardened political topography. Under any scenario, it is just about inconceivable that Democrats could reclaim the House of Representatives. While the Senate could flip to the Republicans, either party’s Senate majority will be too slim to overcome a minority filibuster.

Whatever happens this autumn will probably only intensify divisions over party ideology and tactics: a larger Republican majority would embolden dissidents, a narrower one would increase their leverage. In fact, the only thing certain the morning after the midterms is another two years of the same gridlock that has marked the last four years of US politics. In the one area where Congress may not be able to avoid action – unfolding foreign-policy crises that demand congressional funding or authorisation – the coalitions are such an ideological jumble that no midterm outcome could be parsed as a mandate for a particular policy.

No wave would have the same impact on local politics as past midterm elections, either. In the country’s three largest states, the party controlling the governorship is not seriously threatened this autumn. In those large states whose leaders could be deposed, it will be because of the dynamics of their governance styles – nothing reflective of a broader ideological will.

The one area where control of the Senate will have inescapable relevance is on the Judiciary Committee. Its chairman sets the terms for naming federal judges and five-and-a-half years of a Democratic Senate and president have redrawn the complexion of appellate courts.

A majority of judges there are now Democratic appointees. The triumph for liberalism has been immediate: these are the judges who have, in rapid succession, struck down state gay- marriage bans from coast to coast.

In the next two years a seat or two on the Supreme Court could be in play, too. That body has already had a role in Obama-era policy: it upheld the healthcare bill while circumscribing religious exemptions to its provisions. The same court effectively rewrote the American campaign-finance system with its Citizens United decision. While everyone counts midterm votes, it may be the US’s unelected officials who hold the greatest mandate of all.

Rick Scott, Florida Rejected federal money to subsidise high-speed rail and health-insurance coverage.

Tom Corbett, Pennsylvania Has refused to tax companies “fracking” oil from shale rock.

Scott Walker, Wisconsin Mounted aggressive assault on labour unions representing public employees.

Residents from across the social strata are abandoning Puerto Rico. The Caribbean island has seen 144,000 people leave between 2010 and 2013, says census data; figures not matched by expats returning home. In fact, the country has lost more residents since 2010 than it did during the 1980s or 1990s according to the Pew Research Center.

Hugely influenced by the US due to its commonwealth status – the dollar is the official currency – Puerto Rico’s unemployment rate of 13 per cent is more than double that of its neighbour, which means Puerto Ricans are often motivated to move to the US for economic reasons.