Though tensions between Democrats and Republicans have been festering since the beginning of the 110th Congress, this week’s Senate debate on the Iraq War has pushed the chamber to a new level of partisan acrimony, where even the most seasoned and collegial of Senate elders have abandoned traditional acts of decorum.

“The Senate is spiraling into the ground to a degree that I have never seen before, and I’ve been here a long time,” Minority Whip Trent Lott (R-Miss.) said. “All modicum of courtesy has gone out the window.”

That statement came after a highly charged, all-night debate on a Democratic amendment to refocus the U.S. mission in Iraq and complete a troop drawdown by April 30, 2008. The amendment failed, 52-47, to get the 60 votes necessary to overcome a filibuster, and Majority Leader Harry Reid (D-Nev.) cited the Republicans’ “obstructionist” tactics in his decision to scrap the entire debate on the Defense Department authorization bill.

Reid’s insistence not only on having repeated votes this year on pulling out of Iraq but also on having the overnight session contributed to the explosion of partisan tensions, some Senators said.

“I do think 36 hours with no sleep and the orchestration of a repeat debate of what we just got through two months ago weighed heavily on everybody,” Sen. Johnny Isakson (R-Ga.) said. “It was what it was, but there’s a lot of frustration. It’s a good time for a four-week break.”

Senate Republicans said the clearest evidence that the chamber’s traditional comity has evaporated is in Reid’s repeated decisions to prohibit GOP Senators from giving short speeches when they object to his unanimous consent requests. Reid first began using the tactic against a handful of GOP conservatives during last month’s bitterly fought immigration reform debate.

Sen. Arlen Specter (R-Pa.), the most recent victim of that tactic, gave an indignant speech on the floor Wednesday to protest what he said was Reid’s lack of respect for fellow Senators.

Though Specter acknowledged that Senate rules do not afford lawmakers the right to give speeches following unanimous consent requests, the veteran Pennsylvania moderate said, “It has been common practice in this body to allow a Senator who reserves the right to object to make a statement as to why the objection is being lodged.”

Specter went on to ominously state that Reid’s insistence on the rules could come back to haunt him.

“Those practices I think are not only rude, but dictatorial,” he said. “And if those technical rules are applied — and any one of us can do it — this body will cease to function.”

Republican sources said that beyond Specter, both Lott and Minority Leader Mitch McConnell (Ky.) were taken aback this week when they were denied recognition typically afforded the minority. Lott and Specter — Senators who often work with Reid and Democrats on the floor and on legislation — were particularly incensed with what they viewed as Reid’s disregard of Senate decorum and protocol.

Specter said that Lott declined Reid’s offer to publicly apologize.

One senior Republican aide said Reid — by refusing to allow GOP Senators the opportunity to answer him when addressed — sent a clear signal to the minority of, “To heck with you, your views don’t matter.”

“Not only is violating common courtesy unlike him, it’s not conducive to running the Senate in an effective manner,” the aide said of Reid.

Sen. John McCain (R-Ariz.), who led the GOP debate on the Defense measure, said what occurred over the course of the past two days — and the past two weeks — demonstrated that the “climate here is very bad” and is “part of the whole environment” of the Senate these days. The Iraq War is just one factor contributing to the heightened partisanship in the chamber, McCain added.

But it isn’t just Republicans who are complaining about the breakdown of the chamber’s otherwise civil atmosphere. Senate Democrats countered that they also have been on the receiving end of what they consider ungracious behavior by their GOP colleagues.

In what appeared to be a slap at Democrats on Wednesday, McConnell turned his back on Reid and the Democratic side of the chamber while speaking about the Democratic amendment to refocus the U.S. mission in Iraq.

McConnell spokesman Don Stewart said the Minority Leader was simply addressing his fellow Republicans as he often does when many are gathered in the chamber. More than 70 Senators — roughly half Republicans, half Democrats — were present for the post-vote debate.

But Senate Democrats have said repeatedly that they are being forced to use heavy-handed tactics because the minority refuses to adhere to the traditional courtesy of allowing the Majority Leader to conduct the bulk of the Senate’s business without first having to file procedural motions to limit debate. Republicans have objected to a little more than half of Reid’s requests to begin debate on both controversial and bipartisan bills, resulting in Reid having to file time-consuming cloture motions to cut off prospective filibusters.

“Who’s been asking for these cloture votes?” asked an exasperated Majority Whip Dick Durbin (D-Ill.). “Republicans.”

McConnell has “lost control of his caucus on this matter,” Durbin said of what he believes is McConnell’s inability to convince conservatives in the Republican Conference to pick their battles.

Reid spokesman Jim Manley declined to comment specifically on why Reid has been prohibiting GOP Senators from making short objection speeches, but he indicated that Democrats need to fight back against the GOP’s blocking strategy.

“It’s become pretty evident in recent weeks that there’s been a decision by the Republican leadership to block the Senate from doing all but the most routine and noncontroversial legislation,” Manley said.

Meanwhile, debate on the Defense bill has stopped for the time being, with Reid saying he would bring it back up once it is possible to “pass a Defense authorization bill, but with a deadline dealing with Iraq.”

For the moment, Democrats have been able to put a lock on the Republicans’ procedural objections by bringing up a higher education reconciliation bill that is privileged under the rules and cannot be filibustered. But that measure was taken up only after Republicans blocked Reid from quickly beginning debate on a Homeland Security spending bill.

Reid has tasked Durbin with negotiating a deal with Lott, McCain and Armed Services Chairman Carl Levin (D-Mich.) on how to resume consideration of the Defense measure.

However, McCain questioned whether the DOD bill would rear its head again in the next two weeks: “Without a certain level of cooperation it’s almost impossible. It will be difficult to make it out in time, make it out by August. And the fiscal year ends the first of October.”