Controversial sermons by his former pastor appear not to have hurt Barack Obama's standing in the Democratic race for the presidential nomination, a new tracking poll finds.

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The national Gallup Daily poll also found that Republican John McCain continued to lead both Obama and Hillary Rodham Clinton by small margins in one-on-one hypothetical match-ups.

Gallup showed Obama maintaining his slight lead over Hillary Rodham Clinton, 47-46 percent -- a margin within the poll's margin of error.

The results are based on a March 18-22 survey of 4,385 registered voters, with a sampling error plus or minus 2 percentage points, Gallup said.

Clinton led the poll by a small margin in the days after fiery sermons by the Rev. Jeremiah Wright began to be played repeatedly on cable news channels and the Internet.

According to Gallup's latest five-day average, from March 18 to 22, McCain holds a 3 percentage point lead over Obama, 47-44 percent, and a 2-point lead, 47-45 percent, over Clinton.

The general election results were based on March 18-22 surveys of 4,385 registered voters, with a margin of error of plus or minus 2 percentage points.