President Bush spent twice as much as Democrats in just four weeks on the air, pouring about $40 million into television and radio commercials that championed his record and assailed John Kerry's.

Kerry, the presumptive Democratic presidential nominee, spent about $6 million on ads during the same period. But his campaign has been helped by liberal, outside groups that have spent another $14 million on commercials, allowing the Democrats to pull even or ahead of Bush in some media markets in competitive states.

Still, with $110 million in the bank, Bush has been burying Democrats since March 4, when he first went on the air with heavy levels of television advertising in 18 states, on national cable networks and on radio stations nationwide.

It's unclear what effect Bush's onslaught has had on the race, particularly in battleground states where the most ads are running. Polls show Bush and Kerry remain in a virtual tie compared with early March when Kerry — on a bounce after a string of primary victories — lead Bush, who had yet to begin active campaigning.

The surveys also show Kerry losing ground on domestic issues, such as jobs and health care, which pollsters attribute to the ads and daily criticisms of Kerry by Republicans, including Bush and Vice President Dick Cheney (search).

"It makes you feel like it's post-Labor Day," said Scott Reed, a GOP consultant who ran Bob Dole's (search) 1996 campaign.

Bush's ads, a new one is released every couple of days, are meant to remind voters of his strengths and define Kerry negatively for voters — as weak on defense and the economy — before the Democrat has a chance to project a positive image. Bush will start running a spot Saturday that portrays Kerry as a serial tax-raiser.

Overall, Bush's positive commercials run more often than his negative ads. But the negative spots typically receive more free exposure from the media because of their content.

Bush has spent the most on TV ads over the past month, about $6 million, in Florida, the state where the close 2000 election was decided. Ohio and Pennsylvania follow at about $3 million apiece. Both states were decided by tight margins four years ago and are considered hot spots again this year.

Democrats contend they don't have to match Bush dollar-for-dollar to remain competitive.

"The key is to be at least at a 2-to-1 ratio," said Steve Murphy, a Democratic media strategist who managed Dick Gephardt's (search) presidential campaign.

Kerry has focused his television advertising on 17 states over the past month, and was to run a commercial Friday claiming that Bush's economic policies caused jobs to move overseas.

At the same time, the Media Fund (search), three affiliates of MoveOn.org (search) and, to a lesser degree, other liberal groups combined have poured roughly $14 million into ads that assail Bush in key media markets.

The AFL-CIO (search) entered the fray Thursday with an ad in 11 states that juxtaposes Bush's statements on the economy in his State of the Union address with comments from Americans who say his efforts haven't helped them.

Bush's campaign and the Republican Party this week filed a complaint with the Federal Election Commission (search), accusing Kerry of illegally coordinating advertising with outside groups. Kerry and the groups deny wrongdoing.

Strategists say spending the most money doesn't automatically translate into a White House win because paid advertising matters less in presidential campaigns than in other elections. And, they say, it's become less effective in light of technological changes — like the Internet, TiVo or MP3 players — that allow people to tune out commercials altogether.

But advertising does give Bush an edge because he can ensure that his precise messages — instead of those filtered through the news media — dominate TV and radio, said Martin Kaplan, a professor at the University of Southern California's Annenberg School for Communication.

Still, Kaplan said, Bush runs a risk because "saturation can be a turn off to voters."

Ad spending this year by both sides, meanwhile, is far ahead of where it was four years ago.

In June 2000, the first month of advertising for that year's general election, Bush and the Republican Party and Al Gore (search) and the Democratic Party spent a combined $10 million — one-fourth of what Bush alone spent in his first month on the air this year, according to the Wisconsin Advertising Project at the University of Wisconsin-Madison.