For three-and-a-half years, Scott Bloch has managed to hang onto his job as head of the federal government’s Office of Special Counsel, despite a flurry of allegations about anti-gay discrimination, cronyism, political use of his office, retaliatory firing of staff, and general incompetence. He hung on, kept his head down — and now he is suddenly emerging, unexpectedly, with a full-scale investigation of Karl Rove’s White House political operation.

“I thought it was a joke,” says Congressman Barney Frank, who has spent the past three years trying, without success, to get Bloch to acknowledge the right of federal employees not to be fired for being gay. “This is the least credible investigation I’ve ever seen. It’s just bizarre.”

Bloch, whose office typically investigates federal employee complaints, such as retaliation for whistle-blowing, told the Los Angeles Times this week that he “will not leave any stone unturned” in this investigation. He wants to know whether US Attorneys were fired for political reasons, what happened to those Republican National Committee e-mails missing from laptops used by Rove’s staff, and whether the White House pressured appointees to discharge their duties with an eye toward party politics.

So the question is, will Bloch be Rove’s worst nightmare, striking from within the party, or will he act as Rove’s protector, whitewashing the scandals in-house and declaring them clean?

Frank suspects the latter, and with good reason. Bloch is a die-hard conservative whom Bush stood by when congressional Democrats assailed him. Moreover, Bloch told the Times that his investigation would work independently of others, including House Democrats, which could allow him to bury unsavory tidbits. This is a highly unusual — unprecedented, even — use of the Special Counsel’s powers, making it irregular to the point of odd.

And yet it’s also possible to imagine the ultra-religious Bloch launching this inquiry as a righteous crusade. He has, after all, used his office regularly to enforce the Hatch Act, which bars employees from using federal resources for political purposes. Perhaps he has found a calling in exposing those who bend their offices to political ends, and has decided to go after the worst offenders, right in the White House.

Frank isn’t buying it. “This is a pre-emption, trying to cover up and not have a real investigation,” he says. “I’m appalled.”