Washington ? A growing stack of problems, from questions about his military record to faulty intelligence about Iraq, has thrown President Bush on the defensive, driven down his poll ratings and caused Republicans to fret.

If the election were today, Democrat John Kerry would beat Bush, according to some polls that are causing GOP anxiety.

Bush’s campaign strategists insist the race is exactly where they thought it would be because of all the attention on Democrats during the presidential primary season. They say the president will rebound when he steps fully into the campaign, taps his $100 million-plus political war chest and unleashes a torrent of television ads next month.

One of Bush’s biggest problems concerns his credibility, the idea that he’s a leader who speaks the truth and isn’t afraid to level with people. It was one of the attributes he stressed four years ago in trying to distinguish himself from President Clinton.

Now, Bush is getting the lowest ratings of his presidency on whether people view him as honest and trustworthy.

The credibility problems became noticeable last month when Treasury Secretary Paul O’Neill asserted that Bush began laying the groundwork to invade Iraq just days after taking office in 2001. Then former weapons inspector David Kay came out with his headline-grabbing conclusion that Saddam Hussein did not have the weapons of mass destruction that Bush claimed he had as America went to war.

“Obviously there have been some severe jolts to his credibility and it’s showing up in a bunch of polls,” said Mark Schulman, who conducts national surveys and is not attached to any candidate.

Credibility questions are just one of Bush’s headaches. Americans are still worried about the economy and the loss of 2.3 million jobs on Bush’s watch. Politically important states like Ohio, Pennsylvania and Michigan are struggling with the disappearance of good-paying manufacturing jobs.

And then there is Iraq, where more than 500 Americans have been killed.

Kerry and other Democrats have used the election primaries to criticize the president on the war, the economy, jobs, leadership, trustworthiness and other issues.

Bush’s job approval rating — in 60s and high 50s most of last year — now is in the high 40s to low 50s in many polls, including 47 percent in an AP-Ipsos poll last week. An ABC-Washington Post poll this week found that just more than half of respondents, 52 percent, viewed him as honest and trustworthy, while 45 percent did not.

“It’s early in the game. But if I were Bush looking at the poll numbers now, there are causes for concern,” Schulman said.

Questions about Bush’s service in the Texas Air National Guard persisted throughout the week and kept the White House on the defensive, as Democrats played up Kerry’s war-hero image.

Striking back, Bush’s campaign released its first direct attack on Kerry in a video that called him “unprincipled” and “brought to you by the special interests.” The video was sent via the Internet to millions of people.

The administration also is stepping up its economic sales job. Treasury Secretary John Snow, Commerce Secretary Don Evans, Labor Secretary Elaine Chao and Small Business Administrator Hector Barreto will go to Washington and Oregon next week to promote Bush’s economic policies.

Bush will go to Florida on Sunday to open the Daytona 500 in front of NASCAR fans, an important group of voters, and Tuesday he’ll speak to a military audience at Fort Polk, La.