Enough Republicans joined Democrats in order to restrict the commander in chief's military power against Iran.

Eight Republican senators signed off on Democratic Virginia Sen. Tim Kaine's resolution Thursday to restrict Trump's power, including Sens. Lamar Alexander of Tennessee, Bill Cassidy of Louisiana, Susan Collins of Maine, Mike Lee of Utah, Jerry Moran of Kansas, Lisa Murkowski of Alaska, Rand Paul of Kentucky, and Todd Young of Indiana. The theme that united them was the constitutional responsibility of Congress to declare war.

Paul argued that his vote was not because of partisan disagreement. Rather, he insisted that Congress is the only branch of the government with the constitutional authority to declare war. "For me this debate is not about party. I have supported the Constitutional mandate that Congress must declare war under both Democrat and Republican Presidents and I will continue. For me this debate is not a dry and esoteric debate, it is a debate about life and death," he said in a tweet.

For me this debate is not about party. I have supported the Constitutional mandate that Congress must declare war under both Democrat and Republican Presidents and I will continue.



For me this debate is not a dry and esoteric debate, it is a debate about life and death. — Senator Rand Paul (@RandPaul) February 12, 2020

Lee also invoked similar reasons for his support of the resolution, asserting that the vote would be a demonstration of strength to the rest of the world.

“What the American people and the entire world will see from the debate we’re about to have in the Senate is that there is abundant support for the United States taking tough positions with regard to Iran,’’ Lee said Wednesday. “And as part of that we want to make sure that any military action that needs to be authorized is in fact properly authorized by Congress. That doesn’t show weakness. That shows strength.’’’

Collins also joined with Democrats in support of the resolution so that Congress would not "abdicate" its responsibility to declare war. "Although the president as commander in chief has the power to lead and defend our armed force and respond to imminent attacks, no president has the authority to commit our military to a sustained conflict," she said.

However, Trump's allies have pushed back on their reasoning, saying that the War Powers Act, which limits sustained military conflict as ordered by the president, is unconstitutional.

“I’ve had a long-standing opposition to the War Powers Act. I think it’s an unconstitutional intrusion on the ability of any commander in chief to defend the nation," said Republican South Carolina Sen. Lindsey Graham.

Neither chamber is likely to garner the two-thirds majority needed to override the president's veto, so the future of the bill remains uncertain.

[Opinion: Nancy Pelosi is right about Congress's war powers]