As President Obama launches his 2012 campaign, his poll numbers with Democratic voters aren’t that great. The latest YouGov/Economist poll has him at 74% approve/20% disapprove among Democrats, which is in the ballpark of a DailyKos poll from last week. And if you look at Pollster’s current poll of polls, 79.1% of Democrats approve and 15.2% disapprove.

You might think, hey, 80 percent approval’s not so bad. But George W. Bush enjoyed a 94% approval among Republicans in May 2003 and a year later, he won by just a single state — the narrowest re-election by an incumbent since Woodrow Wilson.

And even more troubling for Obama is that he’s underwater with independents, 40/51.

One of the sour note’s from Obama’s 2012 announcement email was this line:

So even though I’m focused on the job you elected me to do, and the race may not reach full speed for a year or more, the work of laying the foundation for our campaign must start today.

Obama’s problem is that 20% of his own party — and the majority of independents — don’t think he’s doing the job we elected him to do.

And since hectoring the base was a miserable failure in 2010, the question is: how is Obama going to get that 20% to turn out in November 2012?