WASHINGTON (CN) — Save for one astonishing defection, Republicans cemented what Democrats long suspected would be the preordained conclusion of the Senate proceedings on Thursday: a speedy acquittal without witness testimony to further stain President Donald Trump’s legacy as the third impeached commander-in-chief in U.S. history.

Reached within about 30 minutes, the 48-52 vote on the abuse-of-power article of impeachment marks the GOP-dominated Senate’s fatal blow to charges sent by the Democratic-controlled House of Representatives. The Senate killed the other article of impeachment, obstruction of Congress, with a 47-53 vote is ongoing.

Before a final verdict was rendered, Senator Mitt Romney roiled Republican expectations when he announced his decision to acquit Trump on the first article of impeachment: abuse of power.

“I will tell my children that I did my duty to the best of my ability,” Romney said. “I will only be one name among many. No more, no less to future generations who look to the record of this trial. They will note I was among the senators who determined what the president did was wrong, grievously wrong.”

Romney’s was the lone change between the votes on the two articles. The monthslong impeachment battle began in earnest when a whistleblower, who would later be vilified by the White House, filed a complaint last year with Inspector General Joseph Maguire with the Office of the Director of National Intelligence.

The complaint asserted that on a July 25 call, Trump solicited Ukrainian President Volodomyr Zelensky to announce an investigation into former Vice President Joe Biden, Biden’s son Hunter and Burisma Holdings, a Ukrainian-owned energy conglomerate that counted Hunter as board member. A rough transcript of that conversation would later bear out the whistleblower’s story that Trump sought an investigation of his anticipated 2020 election rival.

“I would like you to do us a favor though, because our country has been through a lot and Ukraine knows a lot about it,” Trump told his Ukrainian counterpart.

Trump’s request came while he actively froze military aid to Ukraine that had already been approved for disbursement by the Department of Defense weeks earlier on June 18. This request, reportedly at the direction of Trump, came July 12 — almost two weeks prior to the now-infamous call.

Just one day after the House formally delivered articles of impeachment to the Senate, the Government Accountability Office, an independent federal watchdog, concluded on Jan. 16 that President Trump broke the law by withholding the aid to Ukraine for personal reasons.

Though the intelligence community deemed the allegations in the whistleblower’s complaint “urgent” and “credible,” Maguire, appointed by Trump for the role, initially withheld details about its contents to Congress citing concerns over executive privilege.

This early fight over executive privilege catalyzed the investigation by the House of Representatives into Trump’s unchecked wielding of power and ultimately his decision to obstruct all requests by Congress for records and witness testimony, even though he never actually claimed executive privilege at any point before or during impeachment.

A federal judge called this assertion of immunity unfounded, saying in a 120-page ruling that “presidents are not kings” and could not dictate ownership over the testimonial immunity of his aides.

Despite this, Trump’s defense attorneys, including Alan Dershowtiz — the retired Harvard Law professor and former attorney to O.J. Simpson and Jeffrey Epstein — argued at trial that President Trump he could abuse his power to stay in office if he believed it was in the public interest to do so.

The president was also represented by personal attorney Jay Sekulow, White House counsel Pat Cipollone, deputy counsel to the president Patrick Philbin, former independent counsels in the impeachment of President Bill Clinton Kenneth Starr and Robert Ray, private attorney Eric Herschmann, and special adviser Pam Bondi, the former Florida attorney general who in 2017 refused to investigate Trump University for fraud.

Wednesday’s vote to acquit aligned with similar decisions by senators who united behind their parties on amendments to an organizing resolution offered by Senate Majority Leader Mitch McConnell as the trial began.

That organizing resolution called for a debate on additional witness testimony, a sticking point throughout the trial for all parties, including House impeachment managers Adam Schiff, Zoe Lofgren, Val Demings, Hakeem Jeffries, Sylvia Garcia, Jerry Nadler and Jason Crow.

Senate Minority Leader Chuck Schumer offered four amendments to the resolution. One of his sought-after changes called for former national security advisor John Bolton to testify. Others sought to subpoena documents related to aid restrictions to Ukraine from the State Department. All amendments failed along party lines.

Ahead of the vote Wednesday, Nadler told reporters he “will likely” subpoena Bolton though the timeline for his appearance in the House is unclear.

Bolton’s forthcoming book, “The Room Where It Happened: A White House Memoir,” reportedly details explicitly Trump’s direction to hold the aid to Ukraine until an investigation into the Bidens was announced by Zelensky.

As trial entered its last phases, only a few members defected from their party’s vote including Democratic Senator Joe Manchin, a West Virginia politician struggling for political survival in the heart of Trump country.

Offering a third way between the White House and his party, Manchin proposed a censure resolution from the Senate floor on Monday. This option, he argued, would have united members of both parties while admonishing Trump’s behavior as unethical.

Despite not backing Manchin’s calls for censure, Republican Senator Susan Collins of Maine, who also voted against hearing additional witness testimony last week, made clear during her floor speech Tuesday she believed Trump’s conduct was wrong.

Democrat Senator Doug Jones, whose home state of Alabama went for Trump by almost 30 points in 2016, announced just hours before the final vote that he would convict Trump. Jones said he was swayed by the political entrenchment of other senators’ views.

Republican Senator Mitt Romney of Utah also defected Wednesday and announced he will vote to convict Trump on abuse of power. Romney, his voice often wavering during his remarks, said the decision to break ranks with the GOP caused him serious consternation but that Trump’s actions were “wrong, grievously wrong.”

Analyzing the vote to exclude additional witness testimony from trial, Brian Kalt, a law professor at Michigan State University, told Courthouse News he felt a trial without witnesses was always Trump’s goal since it would likely result in an acquittal with what he perceives is minimal sustained damage to his image.

Even if Democrats held a majority chokehold over the Senate, lawmakers still would not be able to sway 14 Republican senators into convicting the president for abuse of power and obstruction of Congress, Kalt said.

As for the constitutional implications of the acquittal, Kalt said he was skeptical such a decision would shake the foundation of democracy.

“The bar for high crimes and misdemeanors is very low,” Kalt said in an email. “The limit is that in addition to being a high crime or misdemeanor, the Senate must agree that it’s worth removing someone over. The Senate didn’t think that this time. Next time, who knows? “But the test remains the same. To the extent that this represents a degrading of our standards, that’s not because the constitution changed, it’s because our politics have changed.”