42%

Down three points in two days:

The Rasmussen Reports daily Presidential Tracking Poll for Tuesday shows that 24% 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 -20 (see trends).

The Presidential Approval Index is calculated by subtracting the number who Strongly Disapprove from the number who Strongly Approve. It is updated daily at 9:30 a.m. Eastern (sign up for free daily e-mail update). Updates are also available on Twitter and Facebook.

Overall, 42% of voters say they at least somewhat approve of the president's performance. That is the lowest level of approval yet measured for this president. Fifty-six percent (56%) now disapprove of his performance.

That's not an oil slick in the Gulf, that's Obama's credibility melting away.