Ahem, Mr. President - about those 150,000 jobs you said you created...

It turns out the president's claim is really an estimate of what his economic advisers think the stimulus bill is doing, and not based on any evidence of its actual effects.

We asked the White House for substantiation of Obama's claim, and a spokesman responded that the figure comes from a recent estimate by the Council of Economic Advisers. "Because the baseline for employment is obviously still strongly downward," the spokesman told us, "the estimate does not mean that employment has risen by 150,000. Rather, it means that employment is 150,000 higher than it otherwise would have been." He said the figure is an estimate of people hired to work directly on ARRA-funded projects, plus "jobs created by the tax cuts, aid to the states, and other parts of the ARRA."

So when the president said his stimulus bill "already saved or created" those jobs, he was just giving an estimate produced by his own economic advisers at the White House.

Pollster John Zogby said that after his first 100 days, Obama now embarks on another weighty period in which Americans will want to see evidence that his $787 billion economic stimulus approved in February is working.

"I think by late June, they are going to have to start seeing some of these economic indicators stabilizing or at least some orange cones and hard hats out on the roads -- something that indicates either a stemming of the tide or some kind of progress," Zogby said.

Those who keenly watch the poll numbers also point out that while Obama is personally popular, some of the items on his agenda are less so.