Oregon Representative Peter DeFazio is an unbought and unbossed member of Congress—a true heir to the best tradition of another Oregon rabble-rouser, former Senator Wayne Morse—so it should come as no surprise that the maverick Democrat is responding with appropriate boldness to the flood of corporate cash that threatens to overwhelm the 2010 mid-term elections.

No member of the House has been tougher on Wall Street than DeFazio. And Wall Street is pushing back.

A New York hedge-fund manager dumped $300,000 into a shadowy group that has funded a television campaign seeking to defeat the congressman who opposed the 2008 bank bailout and who has been one of the House’s most dogged advocates for holding bad banks and sleazy speculators to account.

Thanks to the meddling of the Supreme Court, the hedge fund manager was able to fund an assault on DeFazio without having to reveal his identity at the time the attack ads began airing.

But DeFazio went after the culprit and finally unearthed the identity of his attacker, after a required Federal Election Commission document was filed.

So now we know that DeFazio was targeted for defeat by a wealthy Wall Streeter who didn’t want to be held to account—let alone required to pay his fair share of taxes.

DeFazio could get mad at the hedge-fund manager. But dozens of hedge-fund managers, bankers and CEOs are meddling in this year’s elections, spending hundreds of millions of dollars to buy the results they want.

So DeFazio is focusing on the real wrongdoer—the jurist who schemed to make it possible for shadowy players to warp the political process without identifying themselves.

Specifically, the congressman says, he is "investigating" the prospect of impeaching Supreme Court Chief Justice John Roberts.

Roberts, an ardent judicial activist, manipulated deliberations in the case of Citizens United v. FEC in order to create an opening for a sweeping 5–4 ruling that effectively eliminated limits on campaign spending by corporations. That decision helped create the current circumstance, where special-interest spending is shouting down the democratic discourse in states across the money.

Never one to back away from a fight, DeFazio is opening a discussion about whether it isn’t time to hold Roberts to account.

"I mean, the Supreme Court has done a tremendous disservice to the United States of America," DeFazio told The Huffington Post last week. "They have done more to undermine our democracy with their Citizens United decision than all of the Republican operatives in the world in this campaign. They’ve opened the floodgates, and personally, I’m investigating articles of impeachment against Justice Roberts for perjuring during his Senate hearings, where he said he wouldn’t be a judicial activist, and he wouldn’t overturn precedents."

Supreme Court justices, who after their confirmation by the Senate serve life terms, can be held to account only via the impeachment power, which the founders outlined with specific references to their concern about judicial abuses.

Most of the successful impeachments since the founding of the republic have involved jurists, although Supreme Court justices have rarely been targeted.

Could DeFazio make a case against Roberts? By most reasonable measures, yes. The evidence of manipulation of the Citizens United case is well established—under Roberts’s leadership, the High Court went so far as to demand that lawyers resubmit briefs so that they would raise issues that Roberts wanted to address. And plenty of questions have been raised about the Roberts’s ties to political and corporate players that are now taking advantage of the Citizens United ruling.

That said, the impeachment process is rarely quick or easy. And it will be even harder to advance if Republicans—the primary beneficiaries of this year’s corporate spending—take control of the House.

But the founders did not say that impeachment would be easy.

What they said—and what Peter DeFazio recognizes—was that, sometimes, impeachment is the only remedy left to citizens (and congressmen) who would defend American democracy.