Rep. Justin Amash (R–Mich.) today suggested that while he's not necessarily opposed to "additional funding" for border security, he doesn't believe declaring a national emergency is the right way to obtain it.

President Donald Trump declared a national emergency earlier this month after Congress gave him just $1.375 billion of the $5.7 billion he'd demanded for construction of a wall on the U.S.-Mexico border. Trump's plan is to reallocate, via national emergency powers, roughly $3.5 billion from the military construction budget in order to build the wall.

While Republican leaders in Congress endorsed the move, Democrats did not. Last week, more than 200 members of Congress co-sponsored a resolution, originally introduced by Rep. Joaquin Castro (D–Texas), to block the national emergency. The resolution passed the House today in a 245-182 vote. All of the bill's co-sponsors were Democrats, with the exception of Amash.

Prior to the House's scheduled vote on the resolution Tuesday, Amash explained in detail why he opposes Trump's national emergency declaration. "There are a lot of fair arguments being made for additional funding, for additional fencing, for enhanced fencing. But that funding has to go through Congress," Amash told ABC News. "The president doesn't get to just declare an emergency for something that Congress has deliberated many times over the past several years."

Amash explained that Trump has previously signed legislation that did not include the billions he wants in border wall funding. If it wasn't a national emergency then, why is it now? "I think we have to be really careful about proceeding here," Amash said to ABC. "We have to make sure that each branch stays within its own lane and Congress retains its power over the purse."

Amash is chairman of the House Liberty Caucus, which announced its opposition to Trump's national emergency declaration on similar grounds. "Few dispute the president's ability to act quickly to address a real emergency, but simply saying something is an emergency does not make it so and cannot on its own trigger emergency powers," the caucus's statement reads:

VOTE ALERT: HLC statement on #HJRes46, relating to a national emergency declared by the president on February 15, 2019 pic.twitter.com/mPoDwEfyrk — House Liberty Caucus (@libertycaucus) February 26, 2019

Rep. Thomas Massie (R–Ky.), also a member of the Liberty Caucus, said on Twitter that he supports Trump's proposed border wall, but that he'd nevertheless vote in favor of the resolution blocking the emergency declaration. "There is a crisis at our border, but it's not an emergency when Congress doesn't spend money how the President wants," Massie wrote. "The President's constitutional remedy is to veto spending bills that aren't suitable to him, yet he has chosen to sign many bills that did not fund the wall."

According to Amash, many conservative House members feel the same way. "Behind the scenes, privately, many [conservative House members] are very concerned about what the president is doing. And they understand our constitutional system," he told ABC. They "would love the opportunity to oppose him," Amash added, but "they're not going to take it for political purposes."