WASHINGTON - President Bush said yesterday that he planned to travel around the nation to make his case for a new Cabinet-level Homeland Security Department directly to the American public. He insisted, though, that his trips would in no way be motivated by politics.

Bush seemed to be suggesting that he would not use his travels to try to aid Republican congressional candidates or to divert attention away from congressional investigations of Sept. 11 that could embarrass his administration.

"I vow not to play politics with doing what is right," Bush said as he convened his new domestic security advisory council, which will help fine-tune plans for the new department.

With homeland security having become a focal point of Washington in an election year, Bush offered an unsolicited defense yesterday of his intentions.

His comments followed a flurry of complaints from some Democrats and other critics who are suggesting that the White House has scheduled major announcements or events related to the war on terrorism to draw attention away from questions being asked about how intelligence officials handled warning signs before Sept. 11.

Rep. Henry A. Waxman, a California Democrat, noted that Bush unveiled his plan for the new Cabinet-level department on the day that Coleen M. Rowley, the whistle-blowing FBI agent who has accused her agency of mishandling warnings of the Sept. 11 attacks, was testifying in the Senate.

Waxman said Bush "rushed to announce the proposal" and that, "given the sequence, it seems these announcements are very much at the hands not of substantive advisers in the White House, but political and communications advisers."

Emerging is a pattern that could endure through the November congressional elections: As Republicans and Democrats look into intelligence failures and debate how best to guard against future attacks, both parties speak grandly of keeping politics out of the discussion yet keep implying that the other side is politicizing the issue.

Both sides seem mindful of the danger involved in appearing to be leveraging a sensitive issue for political gain. Democrats quickly backed off last month, after the White House accused some of them of trying to capitalize on a report that Bush might have had enough information about a possible terrorist attack before Sept. 11 to warn the country.

Now, it is some Democrats and other critics who have accused the White House of acting on political motives.

In particular, these critics have questioned the timing of the administration's disclosure Monday that it had foiled a plot to attack the United States with a "dirty" radioactive bomb and Bush's roll-out last week of his proposed Homeland Defense Department. The announcements, they note, served to drown out congressional testimony or investigations.

White House officials brush aside such suggestions. "These very few people who want to make such an outlandish political accusation represent the most cynical among the most partisan," Bush spokesman Ari Fleischer said yesterday.

Fleischer rejected accusations that the administration orchestrated for political reasons its disclosure this week that a former Chicago gang member, Jose Padilla, was arrested five weeks ago for plotting with al-Qaida to detonate a dirty bomb.

Fleischer said the detention of Padilla, also known as Abdullah al-Muhajir, was made public this week in part because the Justice Department had to decide whether to bring charges against Padilla or to transfer him to military custody as an "enemy combatant." (It chose the latter option.)

The administration sounded inconsistent Monday about how serious a threat Padilla posed.

Attorney General John Ashcroft said gravely that authorities had "disrupted an unfolding terrorist plot to attack the United States."

But Deputy Defense Secretary Paul D. Wolfowitz said, "I don't think there was a plot beyond some fairly loose talk."

But critics said the announcement seemed part of a broader White House strategy. They say that as soon as Bush began facing questions about what he knew before Sept. 11, the White House began aggressively to seize the message, releasing information it knew would overshadow unfriendly headlines.

"There is a pattern to this," said Laura W. Murphy, director of the Washington national office of the American Civil Liberties Union. "If you begin questioning, the administration response is to say, 'We need more power, or how dare you question us, or guess what we did?' - then they reveal something like the Padilla arrest."

Andrew Kohut, an independent pollster and director of the Pew Research Center, noted that Bush, like any president in a crisis, has the ability to make announcements that command the nation's attention.

Since last month, Kohut said, "there has been a lot of aggressive decision-making at the White House. Is it politics or good policy? That's something only those in the White House know."

Bush's top political adviser, Karl Rove, said several months ago that the White House would use the war on terrorism to try to aid GOP candidates by suggesting that Republicans do a better job of protecting America.

Aides said the trips Bush plans to make will be similar to a stop Tuesday in Kansas City, where he spoke about homeland defense and headlined a fund-raising dinner for Rep. James M. Talent of Missouri, who is running for the Senate.

Speaking about homeland security at the dinner, Bush said that "the United States Congress needs to put political partisanship aside."

His remarks helped raise $400,000 for the candidate.