President Barack Obama’s speech on Wednesday night went about as well as the White House could have reasonably hoped.

According to a snap poll afterward, two out of three Americans who watched the president now favor his healthcare reform agenda. That’s up 14 percentage points from pre-speech levels.

Now, the audience watching the speech was more Democratic that the general U.S. population, according to polls. Still, that was probably a plus considering that one of Obama’s main goals was to shore up support among both moderate Democrats (worried about the budget deficit) and liberal Democrats (concerned that a final healthcare plan would exclude a government-backed option).

But, as the president put it, “there remain some significant details to be ironed out.” And while that process continues, Obama is likely to grow weaker rather than stronger.

It is no coincidence that the lack of progress over the summer coincided with an erosion in the president’s popularity. It was notable that the president led off his remarks with a brief economic update, reminding Americans that while the unemployment rate continues to climb, at least America avoided another Depression thanks to his policies.

But the unemployment rate does continue to climb. And that will continue to erode Obama’s popularity and drain his political capital.

In the next two monthly job market reports from the Labor Department, there is a good chance that one will show an unemployment rate at 10 percent or above. And there is also a good chance that Obama’s approval ratings could dip below 50 percent.

From that vantage point, Obama is in a worse situation than President Clinton, who at least had a brisk economic recovery putting the wind to his back as he pushed healthcare reform.

What this means for Obama is that cooperation with him offers little for moderate, blue-dog Democrats or Republicans. So a final bill could be pretty much a Democrat-only affair, with maybe the exception of Senator Olympia Snow, the moderate Maine Republican.

But that was also the situation before the speech.

And even before Obama spoke, some important liberals — including House Speaker Nancy Pelosi — appeared to be backing down from a demand that a strong public option be ready to go on day one of any new healthcare era.  (But don’t discount the possibility that liberals are still willing to sink healthcare reform if the public option isn’t robust enough.)

So in the end, it’s hard to make the case that Obama’s speech has really changed much of anything. If reform passes, it will be a far more limited bill than what Democrats had hoped for back in January.