Washington (CNN) -- On deadline day, President Barack Obama on Friday sent a letter to Congress expressing support for a bipartisan resolution favoring military operations in Libya.

At issue: The 1973 War Powers Act, which says if the president does not get congressional authorization 60 days after military action, the mission must stop within 30 days.

The president formally notified Congress about the mission in Libya with a letter on March 21, which made Friday the 60-day deadline.

Obama sent another letter Friday to House Speaker John Boehner and three other congressional leaders in which he expressed support for the bipartisan resolution that he said is being drafted by senators John Kerry, John McCain, Carl Levin, Dianne Feinstein, Lindsey Graham and Joseph Lieberman.

The resolution would confirm congressional support for the U.S. mission in Libya, Obama said.

The president did not mention the word authorization in Friday's correspondence.

"It has always been my view that it is better to take military action, even in limited actions such as this, with congressional engagement, consultation, and support," he wrote in the letter obtained by CNN.

Obama emphasized that the U.S. has assumed a "supporting role" under the larger NATO-led operation, but argued nonetheless that U.S. support for the mission "remains crucial to assuring the success of international efforts to protect civilians from the actions of the Qaddafi regime."

"Congressional action in support of the mission would underline the U.S. commitment to this remarkable international effort. Such a Resolution is also important in the context of our constitutional framework, as it would demonstrate a unity of purpose among the political branches on this important national security matter," he said.

A spokesman for Boehner said his office has yet to see the resolution and therefore could not comment on whether the House leadership would be willing to bring it up for a vote.

"We received the president's letter but have yet to see the draft resolution it mentions. No decisions will be made until such a review takes place and we discuss the matter with our members," said spokesman Kevin Smith.

Brooke Buchanan, a spokeswoman for McCain, said he and Kerry have settled on language for a Libya resolution and will likely introduce it early next week.

Perceived inaction on the part of Obama has angered some lawmakers from both the left and the right who rarely agree on anything.

Rep. Brad Sherman, D-California, told CNN before news of the letter broke that he believed Obama was trying to "bring democracy to Libya while shredding the Constitution of the United States."

"He cannot continue what he is doing in Libya without congressional authorization. When a president defiantly violates the law, that really undercuts our efforts to urge other countries to have the rule of law," Sherman said.

Sen. Rand Paul, R-Kentucky, concurred.

"You could say, 'Well, we have a good president, he'll do the right thing.' Well, someday you may have a president who does the wrong thing, and that's why you have rules, because you can never count on people being good people," Paul told CNN, again, before the letter.

He called it "appalling" and a "terrible precedent" to engage in military action without the people's representatives -- Congress -- debating it.

To be sure, presidents in both parties often ignored another part of the War Powers Act -- that the commander-in-chief should get congressional approval before any military action.

Still, in recent years, President Bush did seek and receive congressional authority for Afghanistan and Iraq prior to launching those missions.

But it is virtually unprecedented for a president to continue a mission beyond 60 days without a resolution from Congress.

"Make no mistake: Obama is breaking new ground, moving decisively beyond his predecessors," Yale law professors Bruce Ackerman and Oona Hathaway wrote this week in the Washington Post.

The only thing that comes close is President Clinton's military effort in Kosovo.

He failed to get congressional approval before the 60-day deadline was up. His administration argued that Congress had effectively authorized the mission by approving money for it, and the Kosovo conflict lasted 78 days.

The Obama administration doesn't have that option with Libya, because the Pentagon is using existing money. Congress never specifically funded the mission.

The War Powers Resolution passed in 1973 because of concerns about excess executive power in Vietnam. Congress approved it over President Nixon's veto.

Angry lawmakers in both parties have said part of the problem is that their own congressional leaders are not raising a stink about Obama's failure to come to Congress about Libya.

"Very few people are talking about this; they're just letting the president do whatever he wants, and I think that's Congress abdicating the rule of law and abdicating constitutional restraints that he should obey," Paul said.

Paul and five of his GOP Senate colleagues are thinking about taking this to the Supreme Court, which has never formally ruled on the constitutionality of the War Powers Act.

A spokesman for Senate Majority Leader Harry Reid suggested no urgency to force the president to comply with the War Powers Act when it comes to Libya.

"The administration has done a good job of keeping Congress informed about operations in Libya. U.S. operations appear to be limited and intermittent, but we are examining whether further Senate action is needed," said Jon Summers, Reid's spokesman.

However, House Arms Services Committee chairman Buck McKeon called on Obama to seek authorization. "I would have serious reservations regarding support for any future request for authorization of operations in Libya."

Rep. Brad Sherman, a Democrat, says congressional leaders in both parties are letting this go and shirking responsibility because they don't want to have to take a tough vote on whether to give the president authority for military action in Libya.

"Americans are not of one mind on this, and some of my colleagues would just as soon not do their job because this is a difficult part of it," Sherman said.

Some constitutional and legal experts are watching the president's moves carefully, and are preparing to say R.I.P to the War Powers Act.

Ackerman and Hathaway wrote on the same in the Washington Post op-ed:

"If nothing happens, history will say that the War Powers Act was condemned a quiet death by a president who had solemnly pledged, on the campaign trail, to put an end to indiscriminate war making."