Democratic presidential hopeful Howard Dean (search) began airing a pair of TV ads in New Hampshire Wednesday that criticize his rivals' records on the war in Iraq and prescription drug benefits.

The front-runner hasn't been on the air in the first primary state in nearly two months and one recent opinion poll showed the race tightening between Dean and Sen. John Kerry (search) of Massachusetts, with a margin of 6 percentage points. Other surveys show Dean with a double-digit advantage.

In the 30-second spots, the sweater-clad former Vermont governor talks directly into the camera, highlighting his own record on each issue and assailing the positions of his foes, whom he does not name.

Dean says: "The best my opponents can do" is question the wisdom of the Iraq war only after supporting it and talk about fixing the prescription drug problem instead of actually changing the system.

To date, Dean has spent about $430,000 on ads in New Hampshire, including the two new spots, compared to nearly $800,000 Kerry has spent in New England media markets that broadcast into the early voting state.

Of that, Dean has spent roughly $120,000 over the past 11 days, including the new ads, while Kerry spent nearly $80,000 during the same period.

"It is awfully early in the year for negative ads, even for the most negative campaign in the race. The only plausible explanation is they're seeing their poll numbers heading south," Kerry spokesman Robert Gibbs said.

A Dean campaign official, speaking on the condition of anonymity, said the two ads will rotate in New Hampshire. The official said the Iraq ad — the second Dean has run criticizing his opponents for supporting the war — eventually will be phased out, leaving the prescription drug spot the only Dean ad airing in that state.

That one also began airing in Iowa Tuesday, an indication that Dean is concerned that attacks from his rivals on his Medicare (search) views are gaining ground. In recent weeks, Rep. Dick Gephardt of Missouri has linked Dean to Republicans in the 1990s who tried to limit spending on Medicare.

Aides won't say how much the Iowa ad cost, but that buy was large enough to ensure that the average TV viewer in Iowa sees the spot 10 times over the 10 days it's on the air.

Dean is in a tight race there with Gephardt, who spent another $200,000 on ads in Iowa media markets in the past 11 days, compared to an estimated $170,000 Dean has poured into the state during the same period.

However, Dean still leads in overall ad buys in Iowa, having spent about $830,000 compared to Gephardt's $750,000.

Sen. John Edwards (search) of North Carolina continued to buy ads in Iowa — nearly $250,000 worth in less than two weeks — and still leads among the four candidates in Iowa ad buys, having spent about $1 million. The latest polls show him attracting only 7 percent of likely Iowa voters, trailing Gephardt, Dean and Kerry.