Democratic contenders for president are beginning to challenge President Bush's record on terrorism, arguing that Bush has failed to do enough to prevent another fatal attack on U.S. soil and that the nation is barely safer than it was before Sept. 11, 2001.

The expressions of concern about the nation's safety by Bush's prospective challengers, voiced in interviews, speeches and television appearances during the past three weeks, suggest that the focus of the Democratic candidates for the White House in 2004 will go well beyond the traditional Democratic fare of education, the economy, jobs and health care.

Campaign aides said these early challenges on terrorism signaled what they expected to be a central theme in 2004.

"It's time for us, without regard to party, to say what every American knows: Washington is not doing enough to make America safe," Sen. John Edwards of North Carolina said in a speech on domestic security in Washington last week. "If the administration continues to do too little, it will be too late again."

Sen. Joseph I. Lieberman of Connecticut said the "American people are only slightly safer today here at home than we were on Sept. 11, 2001."

Sen. John Kerry of Massachusetts said the administration has squandered a year since the attacks, by failing to make "the preparations necessary to properly deal with an obvious problem of growing terror and the threat at home."

And Gov. Howard Dean of Vermont said Democrats "have a real opportunity here," noting in particular what he described as the administration's bungling response to the anthrax attacks.

White House officials described this line of attack as risky and unorthodox, with some suggesting that it would make the candidates appear willing to exploit American fears for political gain.

"Any candidate who suggests that when the enemy attacks, the blame lies with the United States and not with the enemy does so at great peril to their own political future," said the White House spokesman, Ari Fleischer.

Edwards urged creation of a domestic intelligence agency with the specific directive to work against terrorism at home. Kerry and Lieberman assailed the administration for holding up $1.5 billion in antiterrorism aid to local police departments and emergency agencies allocated by Congress this year, and Lieberman said the White House should move aggressively to improve protection of borders, ports and transportation systems.

Republicans said they were startled by the brazenness of the Democratic attacks, and suggested they would have little effect.

"It's a very tricky play because you're going to try to assign blame," said Russ Schriefer, a Republican consultant. "It's almost like you're trying to make political hay out of a disaster."