WASHINGTON — Rep. Joaquin Castro jumped headfirst into a political minefield this week when he used a word that does not get thrown around lightly on Capitol Hill: impeachment.

Castro told BuzzFeed on Tuesday that President Donald Trump could face retribution from Congress, including potentially impeachment, if he ordered U.S. Customs and Border Protection to ignore judicial rulings halting his refugee travel ban.

In deploying the provocative idea just 12 days into Trump’s presidency, Castro has taken on the mantle of becoming the first Democrat in Congress to talk explicitly about removing the president from office.

He has landed in the crosshairs of Breitbart, the right-wing news website formerly run by Steve Bannon, now a senior White House adviser. As a result, Castro has attracted significant attention online.

Castro, who is considering a statewide run for higher office next year, contests the way some of that coverage portrays his position, noting that he is not talking about penalizing Trump for the substance of the executive order — although he dislikes it — but for allegedly ignoring judicial stays on the refugee travel ban.

And even if proven true, he is not arguing that the case is a first-time impeachable offense, but rather that Congress should censure Trump first and then take further steps if he does it again, comparing the move to a "brushback pitch" in baseball.

But the San Antonio Democrat told The Dallas Morning News that he will not shy away from continuing to pressure the administration to respect the separation of powers.

“If he did, in fact, intentionally disobey that court order then he should be censured by the Congress,” Castro said, “and if he continues to do that then we should move to remove him.”

Castro has followed up his claim, in case anyone doubted its sincerity, with a series of tweets and TV appearances hammering home his point. And he celebrated Thursday when the inspector general of the Department of Homeland Security announced that he would review the agency's handling of the executive order.

Several news outlets reported over the weekend that U.S. Customs and Border Protection officials refused to stop enforcing the refugee travel ban even after a federal judge had ordered a temporary halt. Democratic members of Congress claimed that officials turned them away when they asked them to follow the court order. The agency has denied that the White House directed officials to disobey court orders, telling BuzzFeed the "process is working smoothly and relatively quickly."

If Pres. Trump ordered CBP to ignore a judicial order he should be censured as a warning. If he does it again Congress should remove him. https://t.co/DPeVgAqk5w — Joaquin Castro (@JoaquinCastrotx) February 1, 2017

Castro has talked in recent months about the possibility of challenging Republican Sen. Ted Cruz in 2018, a decision he has said he plans to make by the spring. Some critics on social media questioned whether Castro's mention of impeachment was a cynical ploy to gain attention from the Democratic base.

Castro rejected the accusation out of hand.

"This issue is much bigger than any one political campaign or senate race. It's bigger than me and it's bigger than Ted Cruz," he said. "This is about the foundation of American society and nobody should play politics with it. I certainly haven't fundraised off of it. This is about the foundations of America."

Calls for impeachment are hardly a new phenomenon in the increasingly polarized atmosphere on Capitol Hill. Dozens of Republicans, including several Texans, suggested impeaching former President Barack Obama at various times in his tenure with a bevy of justifications, from his handling of Benghazi to offering a congressman a job to coax him into dropping out of a Senate race.

Rep. Blake Farenthold, R-Corpus Christi, said at a town hall in August 2013 that Obama could be impeached if Congress investigated whether he was not born in the U.S. — more than two years after the president had released his long-form birth certificate showing he was born in Hawaii.

Rep. Michael Burgess, R-Lewisville, did not cite any justification when he suggested in 2011 that his party could impeach Obama just to stop him from enacting his agenda.

And before that, some congressional liberals talked about impeaching President George W. Bush over the Iraq war and treatment of detainees.

The House has impeached just two of the 45 presidents: Andrew Johnson and Bill Clinton. Both were acquitted by the Senate and remained in office.

Raising the specter of impeachment may be "part of a strategy to deny Trump any breathing room," said Walter Wilson, a political science professor at the University of Texas at San Antonio.

"Democrats, because they are relatively defenseless from an institutional perspective, are trying to energize the base in the only way that they can, which is to make fairly inflammatory statements," Wilson said, also pointing to Georgia Democratic Rep. John Lewis' assertion that Trump is not a "legitimate" president.

Though Castro was the first out front with talk of impeachment, several Democrats have expressed agreement with his push to hold the administration accountable.

"We cannot be shy about what our responsibility is," said Rep. Michelle Lujan Grisham, D-N.M. "If we believe there's a constitutional breach, then we have to go through the process including and up to impeachment on any commander in chief."

Timing has nothing to do with it, said Arizona Democratic Rep. Ruben Gallego. Whether the president is 12 days in or 1,200 days into his term, he argued any potential constitutional violation "requires investigation."

Rep. Norma Torres, D-Calif., said that she is cautious about using the provocative word, "but it's something that would certainly merit an investigation and, if found to be true, impeachment as well."

A poll released Thursday found that 40 percent of voters already want to impeach Trump. But 35 percent supported impeachment even before the refugee order, suggesting the sentiment is motivated more by general antipathy toward the new president than specific legal concerns about whether he overstepped his authority.

Even if Castro is able to rally more Democrats to his cause, a successful impeachment effort would remain extraordinarily unlikely in a Republican-controlled Congress. Though the process only requires a simple majority in the House of Representatives, Democrats would need to get dozens of Republicans to approve the measure. And a conviction requires an even less likely two-thirds vote in the Senate.

Trump would need to be "caught red-handed" doing something flagrantly illegal for Republicans to even consider taking action against him, Wilson said.

"And even then, if Republicans don't fear any great electoral backlash from backing the president, they may still decide not to vote for impeachment," Wilson said.

Pointing to the process against Nixon as an example, Wilson notes Democrats were able to get some Republicans to join their efforts, "but that was a much less partisan era, and it was still controversial for Republicans to vote for impeachment even at that time."

Castro said he will continue to follow the issue closely and will file investigation requests as needed. But he demurred when asked if he thinks the process of censuring Trump would stand any chance of advancing in a Republican-controlled Congress.

“It depends on if they want to do the right thing or not,” he said.

Other Democrats are more forthrightly pessimistic about any chance that Republican congressional leaders would be willing to stand up to Trump if he openly violates the Constitution.

“Absolutely not,” Gallego said. “They’re a bunch of cowards.”