A brawl over presidential pardons punctured the normally courtly ambiance of the Senate on Thursday night, but Republicans and Democrats agreed to bury the hatchet and erase the evidence before the sun rose Friday.

In the heat of a partisan spat, Democrats forced a vote on a nonbinding measure to instruct President Bush not to pardon former vice presidential aide I. Lewis "Scooter" Libby. But there's no record of the 47-49 vote in the daily record of congressional proceedings — or anywhere else.

That's because senators agreed less than an hour later to undo their vote and pretend it had never happened.

It was a short detour from consideration of a popular bill to boost aid to college students. But it was a vivid example of frayed nerves in a chamber increasingly riven by partisan stalemate, on vivid display this week during the all-night Iraq debate.

The debate took a dubious turn just after dinnertime, when Republicans brought up a number of unrelated amendments that Democrats decried as politically motivated.

They included an unsuccessful bid by Sen. Norm Coleman, R-Minn., to bar the Federal Communications Commission from reinstating the so-called Fairness Doctrine that would require broadcasters to balance conservative and liberal content. Another failed amendment by Sen. Jim DeMint, R-S.C., would have required secret ballot elections for the formation of unions, instead of making it optional — a direct challenge to organized labor, a source of strong Democratic political support.

Democrats retaliated with their own partisan salvo, the Libby pardon resolution.

"Regrettably, if you are going to shoot this way, we have to shoot that way," Sen. Ken Salazar, D-Colo., said as he brought up the "sense of the Senate" measure.

What followed was a scene more commonly witnessed on the other side of the Capitol in the more raucous House. As senators hooted and brayed amid calls of "Regular order!", Sen. Jon Kyl, R-Ariz. pointedly noted that it's against Senate rules to call an amendment politically motivated.

After Salazar's amendment failed, Republicans took their turn, offering a nonbinding resolution deploring the actions of Bill Clinton for issuing pardons to the likes of his half brother Roger, and clemency for members of a Puerto Rican nationalist group blamed for bombings in the 1970s and 1980s.

"If the Senate has decided to go into debating the appropriateness of future pardons, there is plenty of material to go around on past pardons," said Sen. Mitch McConnell, R-Ky., the minority leader.

Before that could happen, though, the two leaders cut a deal to defuse the tension. Senate Majority Leader Harry Reid, D-Nev. said his side would take back their Libby amendment — including zapping the vote from the record — if McConnell took back his Clinton swipe.

With that, the Senate got back down to business and completed the education bill in the wee hours of Friday morning.