Rasmussen has historically been among the most reliable polls on elections because they sample likely voters and don't oversample Democrats. They publish a daily tracking poll on Presidential approval, and it's not looking good for Obama right now.
"25% of the nation's voters Strongly Approve of the way that Barack Obama is performing his role as president. Forty-four percent (44%) Strongly Disapprove, giving Obama a Presidential Approval Index rating of -19. Today’s rating is the lowest earned by the president since the passage of his health care proposal two months ago."
According to Rasmussen, Connecticut Attorney General Richard Blumenthal has seen his advantage over Republican hopefuls shrink dramatically following a New York Times accusation that he exaggerated his Vietnam military service. Against Linda McMahon, Blumenthal’s lead is down to just three points.