Sixteen years ago, as the summer of 1994 came to a close, then-president Bill Clinton could see that his party's congressional campaign was in trouble. "Hillary had called our old pollster Dick Morris for his assessment," Clinton recalled in his autobiography. "Dick took a survey for us and the results were discouraging. People didn't feel their lives were improving and they were sick of all the fighting in Washington. Apparently they thought divided government would force us to work together."

That November, Republicans swept Democrats from power in the House of Representatives for the first time in 40 years. In the summer of 2010, the news has been bad for Democrats again. Mired in unemployment, the economy seems to be slowing down rather than speeding up.

Most voters don't think President Barack Obama's policies have had any positive effect, and an increasing number say they are willing to give the Republican alternatives — tax cuts and spending cuts — a try.

Discontented Republicans are fired up about voting; discontented Democrats are likely not to vote at all. And just as in 1994, many independents — the swing voters who hold the decisive votes in close elections — say they like the idea of divided government, with each party keeping the other in check.

Democrats know they are heading for a major setback; the only question is, how big? "It's getting a little late for lucky breaks," acknowledged Geoff Garin, a leading Democratic pollster. "At a certain level, the only thing that matters is economic pessimism, and the level of economic pessimism has gotten worse over the last few months."

Already, Democrats have begun arguing over whether Obama could have played his hand better. Liberals complain that the president has been too ready to compromise; centrists say, on the contrary, that he has made himself look too liberal.

Lack of a vision

Some complain that Obama has failed to offer voters a narrative, an overarching vision of where he wants to take the country. Obama's defenders point to the fact that Ronald Reagan's popularity sank even lower during his first term and argue that there's nothing wrong with this presidency that a good economic recovery wouldn't fix.

True, but if the recovery continues at its current agonising pace, Obama can't count on it for much help this fall. Republicans, of course, are hoping Obama's troubles are like those of another former president, Jimmy Carter, who didn't lose control of Congress but did lose the White House after only one term.

The Carter precedent bolsters a counterintuitive point that Democrats don't like to admit: As Obama approaches his own 2012 campaign for reelection, he may be better off if Republicans win a majority in the House this fall.

"If Democrats keep control of both houses, it will be by the skin of their teeth, but they will still be held responsible by voters for the state of the country in 2012," Whit Ayres, a Republican pollster, said.

"It will probably be easier for Obama to win reelection if Republicans take over the House and Senate. He'd have a Republican Congress to run against."

If that's true, the most interesting historical analogy at the moment isn't between Obama and Reagan or Obama and Carter but between Obama and Clinton, the most recent Democratic president to lose control of Congress and survive to win a second term.

When Newt Gingrich's Republicans took over the House in 1994, Clinton announced that he had heard the voters' message and tacked dramatically toward the centre.

"The era of big government is over," Clinton said. He went on to make limits on domestic spending a centrepiece of his agenda. Then, when Gingrich's Republicans pressed for draconian budget cuts and shut down the government to dramatise their stand, Clinton charged them with extremism — and rallied voters to his side.

Obama may face a similar choice next year if a new Republican majority seeks to cut taxes, slash spending and dismantle his newly passed health care law. Wrestling with a Republican Congress would give Obama a chance to move back toward the post-partisan centre he talked about during his 2008 campaign.

Pulling a Clinton by moving to the centre would be the easiest way for Obama to improve his chances of reelection in 2012. He could then remind voters that he has always promised to cut the deficit, agree with Republicans that deficit-cutting should start immediately, and then wrestle with them over how.

The purer, more difficult way would be to emulate Reagan and announce that he plans to "stay the course". The risk of that strategy, of course, is that he might end up emulating Carter instead.

More than once, Obama has said, "I'd rather be a really good one-term president than a mediocre two-term president." Many of his fellow Democrats hope those aren't his only choices.