The battle between the Obama administration and some members of Congress over the U.S. involvement in the Libyan civil war took stage on Capitol Hill Tuesday in an often contentious Senate Foreign Relations Committee hearing that featured one senator asserting Congress is becoming irrelevant in the matter.

"The administration has basically said there's no need for us to get any kind of resolution from Congress, and yet the Senate today in its urge to be relevant is rushing to give the administration a resolution, even though it's basically saying in this case the Senate is irrelevant," said Sen. Bob Corker, R-Tenn.

Committee Chairman Sen. John Kerry, D-Mass., jumped in to defend the administration against Corker's claim that the administration is going it alone in Libya in violation of the 1973 War Powers Resolution.

"I'm not going to sit here and let everybody throw the dart at the White House saying the president violated this and that when he's the first president to ever say I accept the constitutionality of the War Powers Act; secondly, sent us a letter before the expiration of the time asking us to pass the authorization; and thirdly ... I went to the leaders and nobody wanted to do it," Kerry said. "So here we are."

The hearing comes on the heels of last week's failed House vote to authorize the Libya military mission. But another House bill to pull funding from the operation also went down.

The Obama administration committed U.S. bombers and ships to a NATO campaign that was initially billed as a humanitarian effort, but has now become centered on deposing Libyan leader Muammar al-Qaddafi. The U.S. involvement began in March and the president has committed American forces to the war effort at least through September. The War Powers Resolution requires a president to get congressional authorization for war within 60 days and -- if he doesn't get it -- begin removing troops within 90 days.

The White House contends NATO's leadership role in the operation and the fact that that U.S. forces are only bombing Libyan targets and not exchanging fire with Libyan troops absolves the administration of the need to acquire permission.

Much of the heated back-and-forth between senators on the panel overshadowed the hearing's star witness, lead State Department attorney Harold Koh, who authored a legal opinion saying the president hasn't broken any rules.

"Throughout the Middle East, there is only one situation in which there is a U.N. Security Council resolution, narrowly drawn, in which NATO has agreed to take command of the operation ... and which the president was able to structure the mission so there was limited nature, so the United States would move very quickly into a limited supporting role, where there would be no ground troops so that there would be a limited exposure, where the risk of escalation would be low," Koh told the senators. "In that set of circumstances, the president acted lawfully in proceeding as he did."

Koh has been involved with War Powers Resolution issues in the past and says critics don't understand the administration position and that the War Powers Act, in its current form, is obsolete.

"I think that our theory and legal approach has been dramatically misunderstood," Koh told the panel. "There has been some suggestion we are flouting the Constitution. In fact, we have made it clear we are not challenging the Constitution. ... What we are arguing about is whether a very unusual situation fits within a resolution that has been on the books now for almost 40 years and which was designed to play a particular role and will have to be adapted to play that role effectively in this century."

But Koh's rationalizations for the continued conflict weren't good enough for some on the committee. Sen. Richard Lugar, R-Ind., the ranking member on the panel, said the U.S. has involved itself in more than a limited engagement.

"In this particular instance, our decision was to intervene in a civil war," Lugar said. "And we are continuing to intervene in a civil war. And despite the fact that we talk about limited hostilities, we also talk openly as a government about the end of the Muammar Qaddafi rule… What is the ground rule for dealing with civil war wherever we may deal with it around the earth?"

But the committee's chairman John Kerry says Congress' failure to act already has muddied the definitions of the administration's actions in Libya.

"Don't blame the president, the Congress of the United States didn't do (an authorization) ...  because both leaders in both houses were unwilling at that point and time to do it," Kerry said. "The Senate has been having a very difficult time getting anything done lately."