Democratic presidential candidate John Kerry (search) argues that "over a million more Americans would lose their health insurance coverage" under President Bush in a television ad the Democrat's campaign rolled out Tuesday.

The campaign also is going back on the air this week in Colorado with a moderate level of ads, two weeks earlier than it had planned. The shift comes as polls show the race tightening in the state, which traditionally leans toward the GOP.

The ad, unveiled as Kerry presses his health care plan in Florida, seeks to make the case that the Republican doesn't have much of a record on domestic issues, particularly health care. Bush last week started running an ad assailing Kerry's proposal as "a government-run health care plan."

In response, Kerry released an ad claiming the charge was false and explaining his own plan. His new ad goes after Bush's record, saying it shows "health insurance costs up 64 percent" and "Medicare premiums up by 56 percent." The ad also claims that Bush's plan would "raise insurance premiums for four out of five small businesses."

Steve Schmidt, a Bush campaign spokesman, dismissed the criticism. "The American people aren't going to trust a candidate who empowers bureaucrats at the expense of doctors and patients," he said.

The ad will run in select local media markets in 13 states where Kerry is on the air as well as in Colorado. Kerry hasn't been up there since July.

Bush won the state by 8 percent in 2000, and Kerry's campaign ran ads there in the spring and summer to try to put the state in play. It worked. Bush was forced to spend money there.

However, Kerry pulled down his ads in that state, as well as several others, in August to save money. Under the Democrat's $50 million, two-month ad plan, Kerry wasn't slated to go back on the air there until Oct. 5. However, the race has grown tight in recent weeks. One poll has Bush leading Kerry 46 percent to 45 percent.