WASHINGTON (USA Today) – The GOP-controlled Senate defeated a measure Friday that would have blocked President Donald Trump from launching a military strike against Iran unless he got explicit congressional approval.

The 50-to-40 vote came after a rare congressional debate over war powers and amid escalating tensions between the U.S. and Iran. The measure needed 60 votes to pass. Four Republicans broke ranks to support the measure: Sens. Susan Collins, Mike Lee, Jerry Moran and Rand Paul.

Supporters said the battle would now move to the House, where Democrats hold the majority and have a similar measure in the legislative hopper. And they argued that Friday's vote still marked a significant step in pushing back against Trump's foreign policy.

“A bipartisan majority of the Senate today sent an important message to President Trump: you do not have a blank check to pursue another endless war in the Middle East," said Senate Democratic Leader Chuck Schumer of New York. 

As he left the Senate floor Friday afternoon, Sen. Tim Kaine, D-Va., agreed and added that it helps set up the House for success. 

"We did not win on this vote but forced the vote to happen. We showed a majority of the Senate believes the president is not the king, and can’t go to war on his own," Kaine said, adding that it puts up some "guardrail against the president doing something stupid." 

Kaine pointed to Trump being in Japan for the G-20 summit, which attracts leaders from around the world, and said that it may help cool down the possibility of war. But, he added, "the fact that we were 10 minutes away and the fact that the president said this week that he didn’t need Congress, that should scare everybody. We've got to stay on our toes."

Democrats and some Republicans have grown alarmed by the Trump administration’s rhetoric and actions on Iran.

Trump threatened Iran with “obliteration” on Tuesday, warning that the U.S. would use “overwhelming force” against the country if it attacks “anything American.” And last week, Trump initially authorized a missile strike on the country – in retaliation for Tehran’s downing of a U.S. drone – but the president nixed the military action at the last minute. He said then that he was concerned about Iranian casualties.

This week, Trump has taken a harder line and boasted that any war with Iran would be devastating. "I don't need exit strategies,” he told reporters.

But some lawmakers say a war with Iran would be a prolonged and disastrous conflict – precisely the kind of “endless war” that Trump campaigned against in 2016.

“A war with Iran would be a colossal mistake,” Sen. Tim Kaine, D-Va., said during Thursday’s debate on the measure. Kaine is a chief sponsor of the Senate proposal, along with Sens. Rand Paul, R-Ky., and Tom Udall, D-N.M.

“After 18 years of two wars in the Middle East, both of which where we still have troops deployed, we should not be fomenting, encouraging, blundering toward, rushing into a third war in the Middle East,” said Kaine, who sits on the Senate Armed Services and Foreign Affairs committees.

“It is an America-first idea that we would not want to go and engage in these endless, unfocused, unconstitutional wars,” Rep. Matt Gaetz, a Florida Republican, told Fox News earlier this week. He is co-sponsoring a similar measure in the House with California Democratic Rep. Ro Khanna.