Both Rasmussen and Public Policy Polling have put out surveys today testing President Obama's re-election numbers against potential Republican candidates.

Rasmussen (1,000 LVs, July 16-17, MoE +/- 3 percent) gives us three matchups: Obama vs. Mitt Romney and Obama vs. Sarah Palin, and a third, with Palin as an independent: Obama vs. Romney vs. Palin.

2012 General Election Matchups
Obama 45
Romney 45
Not Sure 3

Obama 48
Palin 42
Not Sure 3

Obama 44
Romney 33
Palin 16
Not Sure 4

Only 21 percent of voters said they think Palin should pursue an independent bid if she lost the Republican nomination, while 63 percent said no.

PPP (577 voters, July 15-16, MoE +/- 4.1 percent) tested Obama against Romney, Palin, Mike Huckabee and Newt Gingrich.

2012 General Election Matchups
Obama 50 (-2 from April)
Gingrich 42 (+3)
Not Sure 9

Obama 48 (+1)
Huckabee 42 (unch)
Not Sure 10

Obama 51 (-2)
Palin 43 (+2)
Not Sure 6

Obama 49 (-1)
Romney 40 (+1)
Not Sure 11

PPP puts Obama's approval rating at 50 percent, its lowest number yet; 43 percent now disapprove.