Inauguration Day highs are not normal, can't be used as any measure for anything, similar to war-declaration-day highs or family-death sympathy highs.

The fact is that overall approval for Obama has risen some when compared to post-election numbers. Gallup has it now at 66%, CNN at 76%, Pew at 64%.  We also know that it is Republican voters who have turned against Obama in higher numbers than they did post-election because as a group they are much more opposed to this particular stimulus package, to the tune of 65% to 70% against.  The increase in overall approval for Obama from post-election numbers has to come primarily from Democrats.  Are some on the left grumbling?  Sure. About 15% of Democrats state that an $800+ Billion stimulus package is not enough to stimulate the economy, while another 15% of Democrats state that the $800 Billion price tag is too high, the rest finds it just about right.  The 15% who find the package to small are likely to be found to the left on the political spectrum of the Democratic party.  Still, many of that contingent is realistic enough to understand that we needed 60 votes in the Senate, which meant having to convince about 8 Republicans and Democratic Blue Dogs to vote for this.  I would have been upset if progressives held clear advantages in the House and had a 60+ share in the Senate and Obama had forced through a centrist bill because he himself is a centrist, but the Senate alignment dictated some of the terms.  I think many on the left are aware of the dynamics and have not turned their wrath on Obama for somehow failing to force or shame the resistant Senators to vote the progressive way, although I acknowledge that some have decided to take that view point and decided to assess blame where IMO it does not belong.

To add to the comment above: Yesterday's CNN poll shows the following:

Ninety-seven percent of Democrats approve of the way Obama is handling his duties as president, the CNN/Opinion Research Corp. poll found. That drops to 76 percent for Independents and 50 percent for Republicans.

http://edition.cnn.com/2009/POLITICS/02/ 09/poll.obama.stimulus/

Ninety-seven percent of Democrats appoving of Obama represents a new high point for him, outside of perhaps inauguration day. I had previously seen 94% of Democrats right after the election, also an incredibly high number of approval from one's own party.

 As often is the case with the more vocal outlets like media personalities and prominent blogosphere writers, it seems that the megaphone of expressed discord shouts loud and therefore leads to a perception of broad based agreement from the same ideological corner.  However, that does not always reflect reality. If it did we would see some drop in popularity amongst Democrats instead of further improved numbers.