Updated

President Bush has pulled slightly ahead of Democrat John Kerry (search) in Florida after several weeks of a withering blitz of political advertising, according to a poll released Tuesday.

Bush had the backing of 51 percent of likely voters, while Kerry had the backing of 43 percent in a two-way matchup in the Mason-Dixon poll taken for the Orlando Sentinel and WESH-TV. Six percent were undecided.

Two polls conducted in early March suggested the race is close in Florida, which was virtually tied in 2000 and was finally awarded to Bush after a U.S. Supreme Court decision.

The Bush advantage may be due to heavy advertising by the president's re-election campaign in Florida.

Since early March, Bush has spent about $6 million on TV ads in Florida, compared with about $1 million for Kerry in the state. Democratic-leaning interest groups have spent another $2 million on anti-Bush ads in the state.

The Mason-Dixon poll of 625 likely voters was taken March 30-April 1 and has a margin of error of plus or minus 4 percentage points.