President Obama jumped ahead of a nameless Republican challenger in Gallup's monthly survey of the generic ballot.
Registered voters shifted toward Obama over the last month, erasing the advantage a generic Republican challenger to the president had enjoyed over the two previous months.
Forty-five percent of registered voters said they would pick Obama, versus 39 percent who would favor "the Republican Party's candidate."
While the generic matchup is an imprecise measure of how Obama might perform against specific Republican candidates, it represents an overall shift in the balance in how voters are thinking about the presidential election, in a broad sense.
The most recent generic test came in a USA Today/Gallup Poll conducted Aug. 4-7, after a politically bruising week in which Obama was forced to relent on a debt-ceiling compromise deal that included only spending cuts and no new revenues, and after the ratings agency Standard & Poor's downgraded its rating of U.S. debt.
The poll has a 4 percent margin of error.