A simple question that distils much of the debate swirling in America's Great Recession election appears to have Democrats tied in knots.

Inspired by Ronald Reagan's winning 1980 election pitch, Republicans have urged voters to ask themselves "are you better off today than you were four years ago?"

Uncomfortably for Democratic supporters, the question has elicited a dizzying array of responses from President Barack Obama's allies, first "no" then "sort of" and finally "absolutely."

Republicans salivated at such rare campaign vacillation -- no doubt sensing a much-needed advantage as polls continue to show a tight race ahead of November's election.

"Apparently, for the 23 million Americans struggling for work, things have improved greatly in the last 24 hours," crowed Republican operative Joe Pounder.

Yet the 44th president's allies may have good reason to prevaricate.

By any measure a large chunk of America is still hurting.

The national jobs numbers are a familiar and lingering stain on Obama's record.

When he took office in January 2009 unemployment stood at 7.8 percent. Within months it had risen to 10.0 percent as the crisis deepened. Today it stands at 8.3 percent.

One in every 686 homes in the United States was in the process of being repossessed in July, according to RealtyTrac, a data provider.

Forty-three percent of Americans say economic conditions are "poor," according to Gallup, a polling organization. Almost two in three think things are getting worse.

According to the Pew Research Center, 49 percent of adult Americans describe themselves as middle class, down from 53 percent in 2008.

Against this backdrop Democrats will spend a large part of their quadrennial convention in North Carolina, which begins Tuesday, explaining why, four years after Obama promised "hope" and "change," things are still so grim.

"We are going to use this convention to answer those questions, we are going to have an honest conversation about where we were in 2008," said Obama campaign spokesman Ben LaBolt.

"We were losing 800,000 jobs a month, 3.5 million jobs lost in the six months before the president came to office, manufacturing was in decline, the auto industry was on the brink."

There appears to be some sympathy for the we-inherited-a-mess argument.

A recent Pew poll showed 44 percent of middle class voters blame the Bush administration for the malaise and 34 percent blame the Obama administration.

Democrats can also take some solace from the fact that the economic picture is slightly better in some key battleground states.

Unemployment in Iowa stands at 5.3 percent, in Ohio it is 7.2 percent, in Pennsylvania it is 7.9 percent and in Virginia it is 5.9 percent.

An honest debate about the last four years would undoubtedly take note of progress made, despite external headwinds and the White House's limited clout in solving economic problems.

Oil prices were pushed higher during the Arab Spring, trade was hurt by Japan's earthquake and tsunami, and fiscal crises continued to crimp spending in Europe and in hard-up US states.

Meanwhile, the Republican-led House of Representatives was hostile to providing more stimulus, which most economists believe could have helped the recovery.

But an honest discussion would also take measure of Obama's initial response, which many critics say was insufficient.

Some of Obama's own economic advisors argued for a much larger stimulus package and even his most die-hard supporters would have to admit efforts to right the housing market have gotten very little traction.

Government-backed mortgage originators Fannie Mae and Freddie Mac have refused to take part in the Obama administration's flagship program to help homeowners by cutting their mortgage debt, leaving it moribund.

Yet according to the Fitch ratings agency, federal policies may have boosted US growth by four percent in the last two years and "contributed to preventing a longer and deeper recession."

That is positive, but hardly translates into a resounding success for Obama.

So when he takes to the hustings on Thursday for his prime-time speech, the president is expected to not only put the past four years in context but spell out what he plans to do in the next four.

The winner in November may end up being the candidate who can convince voters they will be better off four years from now.