Curt Weldon, the ten-term Republican Congressman from suburban Philadelphia, believes there are weapons of mass destruction in Iraq. He claims a secret Pentagon unit, Able Danger, identified 9/11 ringleader Mohamed Atta two years before the World Trade Center attacks and covered it up. He wrote a book last year alleging that Iran was plotting to hit the US homeland.

Now he has uncovered yet another conspiracy: The Bush Justice Department is out to get him, even at the cost of Republicans losing the House.

On the night of Friday, October 13, news broke that the FBI was investigating Weldon for using his stature as vice chair of the House Armed Service Committee to steer nearly $1 million in contracts from Russian and Serbian businesses to his daughter and right-hand man, between 2002 and 2004. Those implicated include two Serbian brothers linked to dictator Slobodan Milosevic; a Russian energy company, Itera, with a notoriously cloudy business history; and an obscure Russian aerospace manufacturer, Saratov Aviation Plant, that “quite unexpectedly” caught Weldon’s eye, according to a company official. At the time of the contracts, Weldon’s daughter, Karen, was a 29-year-old consulting novice. Her associate, local political boss and longtime Weldon ally Charles Sexton Jr., claimed “no special knowledge of Eastern Europe,” according to the Philadelphia Inquirer, and spoke no foreign languages. Weldon’s interventions on their behalf were first disclosed by the Los Angeles Times in 2004. Three days after the October 13 story, FBI agents raided six locations as part of the probe, including the homes of Karen Weldon and Sexton. The Washington Post subsequently reported that evidence had been presented to a grand jury and wiretaps obtained for Washington-area cellphones.

Three weeks before election day, an FBI investigation was the last thing Weldon needed. Even before details of the probe emerged, Weldon had found himself in a close race for the first time since he was elected to Congress in 1986. His opponent, retired Navy Vice Admiral Joe Sestak, who served as director of defense policy at the National Security Council under Bill Clinton, had raised more money than Weldon and assembled an impressive grassroots organization with 2,000 volunteers. The once-solidly GOP Philadelphia suburbs were becoming more independent–going for Democrats in the last four presidential elections–and President Bush’s approval rating lurked at 33 percent in the area. Moreover, the vaunted local Republican political machine in Weldon’s stronghold of Delaware County, featured in political science textbooks as the conservative equivalent to Mayor Richard M. Daley’s Chicago, was showing signs of wear. The race was neck-and-neck, with both parties spending heavily.

Now internal GOP polls show Weldon behind. Congressional Quarterly recently changed its analysis of the race from a “toss-up” to “leans Democratic.” But one thing is for certain: If Weldon goes down, he’ll go down fighting. The FBI probe has brought out the vicious, conspiratorial side of Weldon that’s earned him national notoriety and prompted National Journal to ask last month, “Is he crazy?”

A day after the FBI leak, Weldon’s campaign manager, Michael Puppio, called the charges “preposterous.” In a press release on October 16, Weldon blamed “left wing liberal activists,” most notably Citizens for Ethics and Responsibility in Washington for engaging in “the politics of personal destruction.” CREW did file an ethics complaint against Weldon two years ago and named him one of the twenty most corrupt members of Congress in September. But the group does not control the Justice Department. Republican appointees of the Bush Administration do. Weldon has had a difficult time grasping that fact.

After the raid, Weldon blamed the Sestak campaign for possessing inside knowledge of the investigation and “coordinating” with the DOJ. “That is absolutely a partisan political activity on the part of the Justice Department if it occurred,” Weldon told CBS. He based this allegation on a conversation with a retired FBI agent, who later denied making such remarks. “No, that’s not what happened,” the agent told the Delaware County Times. Added Sestak spokesman Ryan Rudominer: “The idea that our campaign has any influence over the FBI or the Republican-led Justice Department is laughable.”

Weldon’s accusations were a little too far-fetched for even some of his supporters to believe. “I don’t think voters think that the FBI is raiding political offices for the political disadvantage of some candidate or the advantage of others,” says George Twardy, the Republican chairman of Haverford Township, Delaware County’s second largest municipality.

At a subsequent debate Weldon got personal, inferring that Sestak, during his thirty-one-year Navy career, spent his time “drinking out of your wine goblets and being waited on by your sailor servants.”

It wasn’t the first time Weldon insulted his opponent. After Sestak’s 5-year-old daughter was diagnosed with brain cancer and hospitalized in DC, Weldon generated a flap by suggesting she be treated in Philadelphia. He called the cops on an 18-year-old Eagle Scout and Sestak volunteer who was taking notes at a Weldon campaign event. And according to recently disclosed e-mails, the Weldon campaign reportedly compiled a “hit list” of those in the national security field who donated to Sestak.

In a tough re-election race, Weldon was hoping to paint himself as the good ol’ local boy and his opponent as a greedy carpetbagger. “I’m the guy who was poor when I entered Congress and will be poor when I get out,” Weldon told me when I caught up with him at the annual Columbus Day Parade in Havertown, Pennsylvania. “I fit this district like a glove.”

It’s an increasingly difficult argument for him to make. The Sestak campaign seems content to let Weldon self-destruct. The FBI investigation came up only once in a recent debate. But voters in the district, including Republicans, are acutely aware of the scandal–on top of everything else. “You got the [Iraq] war,” says Twardy, a Weldon supporter who’s clashed with the local GOP political machine. “You got the closeness to Bush. And now you got some legitimate criminal investigation, it appears.”

The net effect is that enthusiasm for Weldon among Republicans is not what it was. Twardy recently tried to send out 300 pro-Weldon yard signs to longtime supporters. “People say they don’t want ’em,” he says.