Last night the U.S. House of Representatives unanimously agreed to the formation of a special committee to investigate alleged parliamentary shenanigans that may have altered the outcome of a vote, the Washington Post reports.

The move capped a remarkable day that started with Republicans marching out of the House in protest near midnight Thursday, was punctuated by partisan bickering, and ended with Democratic hopes for a final legislative rush fading. Even a temporary blackout of the House chamber's vote tally board led to suspicions and accusations of skullduggery.

While Democratic leaders hoped to leave for their August recess on a wave of legislative successes, the House instead slowed to an acrimonious crawl that threatened to stretch the legislative session into next week.

The agreement to form a special committee was extraordinary. Such powerful investigative committees are usually reserved for issues such as the Watergate scandal and the funneling of profits from Iranian arms sales to the Nicaraguan contras in the 1980s.

"I don't know when something like this has happened before," said House deputy historian Fred W. Beuttler. He called the decision "incredible."

House Majority Leader Steny H. Hoyer (D-Md.) accepted GOP calls for an investigation. "I do not believe there was any wrongdoing by any member of the House. I do believe a mistake was made," he said. "And I regret it.

Politico.com has lots more here and here. Republicans are also distributing video that, they claim, supports allegations that the vote was "stolen."

Of course, when Republicans controlled the House, there were shenanigans as well. Most infamously, a vote was kept open so Tom Delay would twist arms to ensure a victory. As with earmarks, it seems the new boss is much like the old boss.

UPDATE: Congressional Quarterly has a particularly thorough account of the vote:

The floor confusion arose when, with the tally tied at 214-214, two politically vulnerable Democrats, Nick Lampson of Texas and Harry E. Mitchell of Arizona, went to the well of the chamber to switch their votes to "no." The buddy system would prevent Democrats who voted "no" from being targeted as the deciding vote in future campaign ads. Moments later, three Cuban-American Republicans from south Florida, Ileana Ros-Lehtinen, Lincoln Diaz-Balart and Mario Diaz-Balart, moved to change their votes to "aye."

The five vote switches were called out by the House reading clerk. The two Democratic changes put the tally at 212-216. Ros-Lehtinen's switch made it 213-215. Lincoln Diaz-Balart evened it at 214-214, but a tie vote fails. As the reading clerk called out Mario Diaz-Balart's new vote, the Speaker Pro Tempore, Rep. Michael R. McNulty, D-N.Y., banged the gavel, apparently unaware that the second Diaz-Balart's vote had yet to be counted.

McNulty had his eyes on the electronic scoreboard, which still read 214-214. But almost as soon as the gavel came down, the scoreboard registered Mario Diaz-Balart's vote, pushing the tally to 215-213. The scoreboard showed those numbers and the word "FINAL."

Within a minute or so, a flurry of post-gavel vote switches by Reps. Zack Space of Ohio, Kirsten Gillibrand of New York and Jerry McNerney of California — resulted in an official outcome of 212-216. Boehner was observed switching his vote — a common way to preserve the right to seek reconsideration, and an aide confirmed that the tally board at that point should have read 211-217.

"Shame! Shame!" Republicans chanted across the aisle. Rep. Patrick T. McHenry, R-N.C., thumped the seat of a chair in rhythm with the chant. Rep. Steven C. LaTourette, R-Ohio, repeatedly covered his mouth with his hand, pretended to cough and bellowed a barnyard epithet.

McNulty, whom Democrats often tap to preside over contentious debates, could be heard on television insisting "I called it 214-214."

John Fund has an interesting article on Congressional shenanigans and heavy-handed parliamentary rule in the House of Representatives. In some respects, he notes, this is nothing new, and it's not getting any better:

The breakdown has been a long time coming. In the 1980s, after almost 40 years of control, House Democrats had become arrogant and casually exercised the near-absolute power that body gives the majority. In 1985, Democrats insisted on handing a disputed Indiana House seat to the Democratic incumbent by a four-vote margin despite clear evidence that ballots had been handled in a completely arbitrary way during a special recount by a House task force. In 1987, Speaker Jim Wright held open a budget vote for an extra 10 minutes in a frantic effort to convince someone to change his vote. The maneuver prompted then-Rep. Dick Cheney to call Mr. Wright "a heavy-handed son of a bitch."

Republicans didn't act any better during the reign of Majority Leader Tom DeLay. In 2003, a massive Medicare prescription drug entitlement was passed only after a vote was held open for three hours at 3 a.m. as Mr. DeLay strong-armed reluctant GOP members into voting for it. Votes were held open at least a dozen times during the last years of the Republicans' troubled control of the House.

Democrats issued a report in early 2006 pointing out the abuses of GOP rule. None other than Newt Gingrich admitted that he thought his party was too dismissive of the rights of the minority and risked a backlash if Democrats regained control.

Indeed, that happened with stunning speed after the GOP's fall from power last November. Despite Ms. Pelosi's pledge that "we would have the most honest and open government," the new majority quickly adopted a whatever-it-takes approach to passing legislation. Last week alone, a dubious ethics bill was passed less than 24 hours after being introduced. The bill expanding health-care coverage to children was rewritten at 1 a.m., a rule harshly limiting debate was passed at 3 a.m., and the bill was sent to the floor for a final vote the same day.

Fund argues that it is in the interest of both parties to stop the infighting, but offers no reason to be particularly optimistic.