U.S. Senate Republicans blocked a resolution on Wednesday that would have barred U.S. President Donald Trump from further military action in Venezuela without authorization from Congress, after the Republican president pressured party members who had supported ​it.

The vote was 51-50 for a Republican point of order to dismiss the war powers resolution, as just three of Trump’s Republicans voted with every Democrat in favour of moving ahead and Vice-President JD Vance came to the Capitol to break the tie.

Opponents had argued that the resolution should not move ahead because the U.S. does not currently have troops on the ground in Venezuela, after U.S. forces swept into Caracas on Jan. 3 and captured Venezuelan President Nicolás Maduro.

“We’re not currently conducting military ​operations there,” said Republican Senate Majority Leader John Thune of South Dakota, as he opened the Senate on Wednesday.

“Democrats are taking up this bill because their anti-Trump hysteria knows no bounds.”

The Trump administration argues that Maduro’s capture was a judicial operation to bring him ⁠to trial in the U.S. on drug charges, not a military operation.

Opponents reject rationale

Backers of the war powers resolution disagreed, noting that a ‍large flotilla of U.S. ships is ⁠blockading Venezuela, and has spent months firing on boats in the southern Caribbean ​and Pacific. Trump also has threatened further military action.

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“An argument that the Venezuela campaign is not imminent hostilities within the meaning of the war powers resolution is a violation of every reasonable meaning of that term,” Democratic Senator Tim Kaine of Virginia, a lead sponsor of the resolution, said in a speech before the vote.

The close votes reflected concern in Congress, including from some Republicans, about Trump’s foreign policy and ⁠growing support for the argument that Congress, not the president, should have the power to send U.S. troops to war, as spelled out in the U.S. Constitution.

Trump recently has said the U.S. will run Venezuela for years, told Iranians protesting against their government that “help is on the way” and threatened military action to take Greenland, a territory ‍of NATO ally Denmark.

Administration lawyers blessed Maduro operation

Days before the U.S. military operation that removed Maduro from power, Trump administration lawyers blessed the action by saying it would “not rise to the level of war in the constitutional sense” and would serve “important national interests,” according to a legal opinion that articulates a muscular view of presidential power.

The heavily redacted version of the Justice Department’s Office of Legal Counsel opinion, released this week, shed new light on how the administration came to conclude that it was legally permitted to oust Maduro.

The opinion, dated Dec. 23, was prepared for the legal adviser for the White House National Security Council. The 22-page document was drafted by lawyers at the Office of Legal Counsel, which is historically called upon to resolve thorny questions of law for the executive branch.

In this instance, the opinion wrestles with the question of whether Trump could order the military to aid law enforcement in removing Maduro from power so he could face criminal prosecution in the United States.

The answer, the opinion said, was yes. It cited five separate reasons, including what it said were “severe” allegations against Maduro contained in a drug-trafficking conspiracy indictment; the “numerous other highly dangerous activities” that he and his associates were alleged to be involved in; the possible need of military force to protect civilians in Venezuela and abroad from Venezuela; and the potential that U.S. personnel would encounter an “armed resistance” protecting Maduro.

“Here, we were told to assume that there were as many as 200 armed guards in a literal fort who have been sent from and armed by another country purely to ensure Maduro’s safety,” the opinion said. “This level of expected armed resistance supports the need for military forces to provide security for law enforcement personnel carrying out the rendition.”

Though the opinion does identify what it said were significant risks in the military operation, depending in part on Maduro’s precise location at the time of the action, administration lawyers judged a low likelihood that it would lead to an all-out war that would require congressional approval.

Pressure from Trump

Wednesday’s vote demonstrated Trump’s hold over his party.

It came less than a week after the Senate voted on Jan. 8 to advance the resolution. In that vote, five Republicans joined every Democrat in favor of moving forward, a rare rebuke of the party leader in the Republican-majority chamber.

A man wearing glasses gestures during a conversation with reporters

U.S. Senator Rand Paul of Kentucky, seen speaking with reporters on Wednesday, was among three Republican senators who voted with the Democrats. (Heather Diehl/Getty Images)

Trump responded furiously, saying the five Republicans should never be elected to office again. The five ⁠were Rand Paul of Kentucky, Susan Collins of Maine, Josh Hawley of Missouri, Lisa Murkowski of Alaska and Todd Young of Indiana. Trump’s party holds a 53-47 majority in the Senate.

Trump, U.S. Secretary of State Marco Rubio ​and other administration officials launched an intense campaign to encourage the Republicans to flip their positions and oppose the resolution, calling them repeatedly.

Hawley and Young did so ​on Wednesday.

In a statement, Young said he had received assurances from “senior national security officials” that there are no U.S. troops in Venezuela. “I’ve also received a commitment ‍that if President Trump were to determine American forces are needed in major military operations in Venezuela, the Administration will come to Congress in advance to ask for an authorization of force,” he said.

Even if it passed the Senate, ‍to become law, the measure would have had ⁠to pass the Republican-led House of Representatives and garner two-thirds majorities in both the House and Senate to survive an expected Trump veto.

Trump’s Republicans blocked two previous attempts to advance similar resolutions in the Senate last year.

After Maduro’s capture, some lawmakers, including Democrats publicly and some Republicans behind the scenes, accused the administration of misleading Congress by having insisted they did not plan to force Venezuela to change its government.

In recent days, Trump has posted a meme online showing him as “Acting President of Venezuela” and told the New York Times that U.S. involvement in the South American country would last for years.