It's not the SEC investigation into the activities of the Senate Majority Leader. It's not the plan to divert corporate contributions to Texas in an effort to serverly gerrymander the state's congressional districts, although the central player in that investigation is threatened by this probe as well.

In today's issue of The New York Times, Philip Shenon takes a look at yet another scandal that greatly threatens the Republican hegemony in Washington: the ongoing investigation into the questionable practices of GOP superlobbyist Jack Abramoff and his recently plea bargained former associate, Michael Scanlon -- who previously served as a top aide to then-House Majority Leader Tom DeLay.

The charges against Mr. Scanlon identified no lawmakers by name, but a summary of the case released by the Justice Department accused him of being part of a broad conspiracy to provide "things of value, including money, meals, trips and entertainment to federal public officials in return for agreements to perform official acts" - an attempt at bribery, in other words, or something close to it.

[...]

Scholars who specialize in the history and operations of Congress say that given the brazenness of Mr. Abramoff's lobbying efforts, as measured by the huge fees he charged clients and the extravagant gifts he showered on friends on Capitol Hill, almost all of them Republicans, the investigation could end up costing several lawmakers their careers, if not their freedom.

The investigation threatens to ensnarl many outside Congress as well, including Interior Department officials and others in the Bush administration who were courted by Mr. Abramoff on behalf of the Indian tribe casinos that were his most lucrative clients.

The inquiry has already reached into the White House; a White House budget official, David H. Safavian, resigned only days before his arrest in September on charges of lying to investigators about his business ties to Mr. Abramoff, a former lobbying partner.

"I think this has the potential to be the biggest scandal in Congress in over a century," said Thomas E. Mann, a Congressional specialist at the Brookings Institution. "I've been around Washington for 35 years, watching Congress, and I've never seen anything approaching Abramoff for cynicism and chutzpah in proposing quid pro quos to members of Congress." [emphasis added]

The Abramoff investigation seems to have roped in at least one leading Republican already. Among the documents filed against Scanlon last week was a reference to "Representative #1," who has subsequently been outed -- by his own office -- as House Administration Committee chairman Bob Ney, Republican from Ohio. But as Brookings' Mann rightly notes, the scandal probably doesn't end there. And in the past, voters have not been keen on reelecting incumbents in the wake of systematic scandals racking Congress. For instance, the importance of the House Banking Scandal of 1992 cannot be underestimated when looking at the Democrats' loss of House seats in both the 1992 and (especially) the 1994 elections.

While the Abramoff probe does not threaten as many House members as the 1992 scandal, which broke after news emerged of more than 350 House members of both parties overdrawing on their personal House bank accounts, it is at least as threatening to the majority as its predecessor, given the fact that "almost all of [those involved are] Republicans." So it seems all the GOP leadership can now hope for is for the results of the investigation to be differed until after the 2006 midterms.