The election is less than a week away. Democratic control of the House is in jeopardy. So it's not too soon to start worrying about Darrell Issa.

Never heard of him? That's apt to change soon should Republicans win the House and the hyperkinetic five-term congressman from San Diego assume the chairmanship of the House oversight committee -- and with it the power to scrutinize, and subpoena, the Obama administration.

Issa, a 56-year-old with glossy Jon Hamm looks, was a self-described "rotten young kid" before making a fortune in car alarms and using some of it to run for Congress. (That's his deep voice warning, "Protected by Viper. Stand back.") Since President Obama took office, Issa has reveled in his role as "annoyer in chief," peppering the administration with hundreds of letters raising the specter of wrongdoing and demanding information.

There are two faces of Issa -- Good Darrell and Bad Darrell. Good Darrell sounds responsible, measured, almost statesmanlike. Bad Darrell tosses red meat to a ravenous base.

Good Darrell, writing in USA Today on Oct. 11: "Oversight is not and should not be used as a political weapon against the occupant of the Oval Office. It should not be an instrument of fear or the exclusive domain of the party that controls Congress."

Bad Darrell, to Rush Limbaugh on Oct. 19: "You know, there will be a certain degree of gridlock as the president adjusts to the fact that he has been one of the most corrupt presidents in modern times."

If Issa believes this, he is deranged. If he doesn't and is saying it anyway, he is dangerous. The evidence so far suggests the latter. When Bloomberg's Al Hunt called Issa on his hyperbole, the congressman hemmed, hawed and brought forth a mouse: in-sourcing.

Seriously. In-sourcing, the practice of shifting work from private contractors to government. "I think the process that we're dealing with, where in-sourcing, for example . . . we have every day in the defense and non-defense community, executives of the government tapping people on the shoulder saying, 'You know, your contract's not going to be renewed. We're going to in-source that. You should take this job now for a pay raise,' " Issa said.

Congressional oversight is a crucial function, and having watched a supine Republican-controlled Congress abandon that role during much of the George W. Bush administration, I'd rather have too much than too little.

This is easy to say, of course, if you're not on the receiving end of subpoenas -- and legal bills. Abusive oversight is not the purview of a single party. Power corrupts, but subpoena power tempts. Excesses in the name of oversight can be nearly as damaging to the effective functioning of government as the absence of oversight.

So the question, if Republicans take the House, is whether Good Darrell will triumph over Bad Darrell. Issa's staff said he was too busy for an interview until after Election Day, but sent a list of inquiries that Issa had championed, including into Countrywide's VIP mortgage program, the Minerals Management Service and the salmonella outbreak.

Legitimate areas for oversight, but Issa's larger record does not foretell restraint. His modus operandi has too often been to accuse first -- and keep accusing even in the absence of supporting evidence.

In Issa's world, the administration's dangling of a job offer to Rep. Joe Sestak to drop out of the Pennsylvania Senate primary is "a crime" and an "impeachable" offense, with an ensuing White House "coverup" reminiscent of Watergate.

In Issa's world, the Securities and Exchange Commission's lawsuit against Goldman Sachs in the midst of congressional debate about financial reform "reeks of a political motive," as he told CNBC. Issa demanded an investigation and told Don Imus that the SEC's inspector general launched a probe "because he sees there's something rotten in how [the SEC] did it and when they did it."

Five months, a review of 3.4 million e-mails and 32 sworn interviews later, the inspector general found zero evidence of political considerations or collusion. Issa was hardly contrite that his accusations had proved groundless, saying only that "taking some extra time to address questions surrounding the SEC's decisions is a worthwhile investment."

Sometimes, certainly, the whiff of smoke exposes fire. Sometimes, too, it's worth chasing smoke simply to ensure that no fire is smoldering unseen. But Issa, if it comes to that, must keep in mind: The fireman needs to be careful how he wields the ax.

ruthmarcus@washpost.com