Early last week, Barack Obama cast a ballot in his local Chicago precinct – one of the few places in America where he still remains a popular figure. As he was voting, a man walked past, pointed to a woman standing next to him and said, “Mr President, don’t touch my girlfriend.”

It was a joke and the president handled it with good humour as he poked fun at the man and ignored his request by giving his girlfriend a hug. It was, however, a fitting reminder of Obama’s political standing: not only do his congressional allies not want to be seen with him on campaign trail; his supporters don’t trust him with their partners.

Obama has never been a very popular president. Only for brief periods has he had an approval rating above 50% and his disapproval rating has been higher than his approval rating since May 2013, although the gap has rarely been as wide as it is now. This unpopularity has turned him into the focal point of Republican attacks and a drag on congressional Democrats who are on the ballot this autumn, for midterm elections on 4 November. For those Democrats in states won by Obama’s 2012 presidential challenger, Mitt Romney, Obama has become politically toxic.

To be sure, practically every party whose president has been in power for six years goes through this – it happened in 1958, 1966, 1974, 1986 and 2006, all years in which the party of the White House incumbent got smoked in midterm elections.

But this year there is more than the traditional six-year itch. Crises in Ukraine, Iraq and Syria; hysteria over Ebola; and an obstructionist Republican Congress that is on pace to pass the fewest number of laws in American history, have driven Obama’s ratings further down. What with the gridlock in Washington and the constant drumbeat of bad news from around the world, it’s hardly surprising he is taking most of the blame.

But what has made matters worse is that members of his party are abandoning him. In the last several weeks, his former secretary of state, Hillary Clinton, has obliquely criticised his foreign policy, while his former defence secretary, Leon Panetta, has been more direct in his ingratitude: he accused the president of demonstrating weakness because of his new-found reluctance to use American military force around the world.

 The Kentucky Senate Democratic candidate Alison Lundergan Grimes with former president Bill Clinton backstage at a campaign event. She has repeatedly declined to say whether she voted for Obama. Photograph: Win McNamee/Getty ImagesOn the campaign trail, it has become a game of political obfuscation for Democratic candidates when they are asked about Obama. In Kentucky, Senate challenger Alison Lundergan Grimes refuses to say whether she voted for the president and can barely find it in herself to say a good word about him. Kay Hagan, senator for North Carolina, could come up with only a single example of the president’s strong leadership (the cleanup of the BP spill in the Gulf of Mexico, of all things), and in Alaska, when asked if he’d voted for the titular head of his party, senator Mark Begich said that he had – but that it didn’t matter since the president was “not relevant”. And these are Obama’s political allies.

But the distancing goes beyond politics. Democrats are walking away from Obama’s accomplishments – and none more so than his signature achievement, Obamacare. Grimes blasts the incoherent position of her opponent, Senate minority leader Mitch McConnell, who wants to repeal the policy “root and branch” while keeping the popular healthcare exchange in Kentucky that is a result of, and sustained by, Obamacare. But that doesn’t mean she is vigorously defending the law. While other Democrats have spoken positively about some aspects of Obamacare, few are running on the issue, or trumpeting the good that it is already doing.

In a year in which the biggest challenge facing Democrats is getting their voters to the polls, this is a strategy that seems perversely oriented to alienate core Democratic voters – particularly African-Americans, who are Obama’s strongest backers and the most reliable Democratic constituency. By refusing to back the policies that define the party, they send an implicit message to voters that the unceasing criticism of Democrats from Republicans is in some way legitimate and accurate. The cumulative impact of Democrats trying to strike a non-existent balance between separating themselves from the president and appealing to his political enemies is to provide voters with the sense that their core political beliefs are transitory. So even if they are successful on election day, these Democrats are doing enduring damage to their party and to the ideology underpinning it.

This has been happening for six years. While Republicans have largely spoken with one voice in running down Obama, congressional Democrats have long been weak supporters of his agenda. They have played “every man and woman for themselves” politics. You might even argue that their political vulnerability – and the weakness of the Democratic brand – is worsened by this fact. What else would you expect when you are afraid to give voters a single affirmative reason to vote for your party?

In fairness, however, it’s hard to find an affirmative reason to vote for anyone this time. This is the dirty little secret of the 2014 midterm election – it’s pretty hard to argue that it will matter all that much.

Three years ago – after a plea from an Observer editor to help Brits better understand the increasing insanity of US politics – I noted in these pages that “America is increasingly moving toward a parliamentary system in which politicians, rather than voting along regional lines or in pursuit of parochial interests, cast their ballot solely based on whether there is a D or R next to their name. Such a system might work well in the UK, but in the US … a parliamentary-style system is a recipe for inaction.”

Three years later, things are so much worse. Dysfunction has become the new norm.

So while there are elections in both the US House of Representatives (where every member is up for re-election) and the Senate (where about a third of the 100 seats are in play), the latter is the only real game in town. No one expects the GOP’s hold on the House to change, and even if the Senate flips to the Republicans (an increasingly likely scenario) it won’t dramatically affect the nation’s politics. As long as the GOP controls either the House or the Senate, it can systematically block legislation, obstruct the president’s agenda, shut down the government (or hold it hostage) and continue its four-year pattern of governing while asleep at the switch. It is like having a Labour prime minister with a Tory parliament.

Once it was possible to cobble together groups of congressional Republicans and Democrats to pass bills, but in the modern GOP, nothing is worse than the idea of compromise with Democrats, and particularly not with the much-hated Obama.

For decades the two parties have taken very different views on the role of government, but never has the divide been wider, and at no point since the 1930s has the GOP taken such a radical anti-government position. So if Republicans do take control of the Senate the result will just be slightly more mindless obstructionism than we have already seen over the last four years.

 Former defence secretary Leon Panetta has publicly accused his president of weakness. Photograph: Jonathan Ernst/ReutersThe dysfunction in American politics is so endemic that unless one party can take control of both houses and the White House nothing will change and nothing will get done.

From that perspective, 2014 is merely a skirmish in the bigger battle that is coming – and one in which Obama is likely to play a much less central role. Then, Americans will be selecting a new president along with a new Congress – and it is a year in which Democrats will have the political advantage. With Clinton likely to be the Democratic nominee, her presence on the ticket should mobilise millions more Democrats than this midterm cycle. With Republicans defending far more Senate seats in 2016, that larger turnout will boost the chances of Democrats picking up seats in the Senate. There is even a possibility that the combination of an energised Democratic base and an extreme conservative Republican nominee (someone such as Texas Senator Ted Cruz) could bring the House of Representatives into play for the Democrats. There is also the chance – albeit a very slim one – that Republicans could win back the White House and win the Senate while holding the House.

But it is no exaggeration to say that this is the only real hope of breaking the downward spiral of not just American politics but of American governance. One party must run the table. The other must be vanquished. Period.

This is a very far cry from what Obama imagined six years ago when he ran for the White House. Then he spoke of moving past the Bush years and finding common ground in Washington. The exact opposite has occurred. So while Obama remains the fixation of the 2014 midterms – and there will be plenty of fights to come over the next two years – America is already on the cusp of the post-Obama era and a political battle royal that will drag on long after he has left office.