How U.S. Rep. Joaquin Castro led the Democrats against President Donald Trump's emergency order

The San Antonio Democrat portrayed the resolution as a defense of the separation of powers among government branches. While Sen. John Cornyn said he will oppose the resolution, Sen. Ted Cruz was less clear on his stance.

U.S. House Speaker Nancy Pelosi, flanked by House Democrats including U.S. Rep. Joaquin Castro, D-San Antonio (left), held a news conference Monday about the proposed resolution to terminate President Donald Trump's emergency declaration.

WASHINGTON — The U.S. House of Representatives rebuked President Donald Trump’s emergency order Tuesday to fund a wall along the country's southern border after a 245-182 vote on a measure authored by Democratic Rep. Joaquin Castro of Texas.

“I think it was a strong message that his emergency declaration unconstitutionally strips Congress of power and that it's an attack on the separation of powers enshrined in the Constitution," said Castro, the San Antonio representative whose efforts on the resolution U.S. House Speaker Nancy Pelosi has repeatedly praised. He also called the vote "an acknowledgement that the overwhelming majority of Americans and Texans did not want the president to take money from military construction.”

U.S. Rep. Will Hurd, R-Helotes, was the lone Texan to cross party lines. His West Texas 23rd Congressional District encompasses more of the Mexican border than any other district.

The resolution looks increasingly likely to pass the U.S. Senate. But Trump is expected to veto it, and it is unlikely that Democrats would be able to muster enough Republican support to override that veto.

In the new era of Democratic control of the House, the resolution's passage underscores Castro’s increasing stature within his party's caucus. He is currently mulling a run for U.S. Senate and is also the chairman of the Congressional Hispanic Caucus, a powerful voting bloc. Pelosi credited Castro in recent days for early foresight on the legislation.

“He made sure we were ready,” she told reporters Monday.

The legislation will move to the Senate in coming days. A handful of Republicans are expected to side with Democrats — maybe even enough for the measure to pass the upper chamber.

The Republican opposition to Trump's emergency declaration falls into three categories: Trump’s move neuters one of the most sacred congressional powers (the purse, or control over funding allocations); the order alienates defense hawks in that it could defer military money to the border; and the border barrier makes some vulnerable Republicans uncomfortable about their re-election chances.

As the bill heads to the upper chamber, Sen. John Cornyn of Texas was clear how he felt about it.

“I will vote against the resolution of disapproval," he said.

His Republican counterpart, Sen. Ted Cruz, was unclear on which way he would vote. But the senator said he was worried about how this will impact future presidential administrations.

"I am very worried about the slippery slope that could occur, emboldening future Dem presidents to implement radical policies contrary to law and contrary to the Constitution,” he told Intercept D.C. Bureau Chief Ryan Grim.

After Tuesday's vote, Castro said, “The question for the senators in Texas is: Are you going to stand by while the president strips a bunch of Texans of their land to put a wall up in a way that most Texans disagree with?”