Trump’s impeachment trial was in many ways more a loyalty test for Senate Republicans than a thoughtful examination of the allegations against him.

Republicans have repeatedly decried President Donald Trump’s impeachment trial as a partisan “sham,” depicting it as a nakedly political process orchestrated by Democratic leaders who are still upset over the results of the 2016 election.
The GOP is right: Trump’s impeachment trial has been a proceeding fundamentally driven by partisanship rather than the impartial standards expected of trials. But they’re wrong about who made it that way. 
Republicans ensured that Trump’s trial would be a sham before it even began, and as jurors they set up a trial that would block new witnesses and end rapidly with a predetermined verdict.
‘We all know how it’s going to end’
Even before the House Judiciary Committee voted on articles of impeachment against Trump, Senate Majority Leader Mitch McConnell virtually guaranteed that the president would be acquitted. 
“We all know how it’s going to end,” McConnell told Fox News on December 12. “There is no chance the president is going to be removed from office.” McConnell also said he’d be working in “total coordination” with the White House and Trump’s legal team.
In the days that followed, McConnell and other Republicans, such as Sen. Lindsey Graham, made clear that they would not uphold the oaths of impartiality taken by senators at the start of the trial. 
Graham said he will do “everything” he could to make the trial “die quickly.” 
“I’m not an impartial juror. This is a political process,” McConnell later said.
—CSPAN (@cspan) December 17, 2019
The first Senate impeachment trial in US history without witnesses
In an unprecedented move, Republicans also made sure that no witnesses were called in the trial. All 15 Senate impeachment trials prior to Trump’s included witnesses, including for the only other two impeached presidents, Andrew Johnson and Bill Clinton.
The motion to call witnesses was rejected by Republicans last Friday in a 51 to 49 vote even as new evidence against Trump emerged in news reports, including from the unpublished manuscript of former national security adviser John Bolton, who was viewed by Democrats as a potentially vital witness.
Bolton’s forthcoming book raised the possibility that the White House counsel, Pat Cipollone, the lead attorney on Trump’s defense team, was also a witness to the allegations against the president; a conflict of interest that would typically preclude a person’s involvement as an attorney. But Republicans were apparently unmoved by these revelations. 
Unlike the GOP, a strong majority of Americans wanted witnesses called.
Republicans offered an array of justifications for why they rejected witnesses. They accused House Democrats of rushing the process and said they should’ve gathered the necessary evidence prior to a trial. But their vote against witnesses was a transparent effort to rapidly conclude a trial for a president they’ve struggled to defend.
—John Ratcliffe (@RepRatcliffe) January 31, 2020
And hanging over all of this was the fact the Trump administration refused to comply with the House impeachment inquiry, and sought to block investigators from questioning witnesses or gathering evidence. 
Republican Sen. Lamar Alexander essentially conceded that Trump was guilty of the allegations Democrats laid out, but still voted against witnesses.
Alexander, who is retiring this year, was viewed as a potential “yes” vote for witnesses. But ahead of the vote, the Tennessee Republican made clear he would go against the motion. 
“It was inappropriate for the president to ask a foreign leader to investigate his political opponent and to withhold United States aid to encourage that investigation,” Alexander said in a statement. “The question then is not whether the president did it, but whether the United States Senate or the American people should decide what to do about what he did. I believe that the Constitution provides that the people should make that decision in the presidential election.”
To put it another way, Alexander contended the best route forward is for American voters to decide Trump’s fate in the 2020 election, as he effectively admitted the president solicited foreign interference in that same election. 
Sen. Lisa Murkowski, another Republican who was considered a potential “yes” vote for witnesses due to previous moves that went against Trump, also voted against witnesses and vowed to acquit the president despite condemning Trump’s behavior toward Kiev. Like Alexander, the Alaska senator said voters should decide Trump’s fate. 
“The president’s behavior was shameful and wrong. His personal interests do not take precedent over those of this great nation,” Murkowski said in a speech on the Senate floor on Monday. “The response to the president’s behavior is not to disenfranchise nearly 63 million Americans and remove him from the ballot… I cannot vote to convict.”
—ABC News (@ABC) February 4, 2020
Not a trial, but a loyalty test for Republicans
Here’s what we know: The president pressured a foreign power and vulnerable ally, Ukraine, to dig up dirt on his political rivals ahead of an election year. Simultaneously, the Trump administration froze nearly $400 million in congressionally-approved military aid to Ukraine. The US Government Accountability Office, an independent government watchdog, found that the Trump administration’s decision to freeze the security assistance broke the law.
There’s a mountain of evidence — including a summary of a phone call with Ukraine’s president and testimony from multiple career officials — that taken together suggests Trump deliberately withheld the aid from Ukraine as he sought to push Kiev into announcing investigations he would’ve personally benefited from while running for reelection.
Trump on July 25 asked Ukrainian President Volodymyr Zelensky to launch inquiries into former Vice President Joe Biden and his son, Hunter Biden, and a conspiracy theory that Ukraine, and not Russia, interfered in the presidential election. The president repeated this request of Ukraine regarding Biden, a leading contender for the 2020 Democratic nomination, on live television on October 3. 
—CSPAN (@cspan) October 3, 2019
For context: While Biden served as point man for the Obama administration on Ukraine, his son was on the board of a Ukrainian natural gas company, Burisma Holdings. Though this raised ethical questions and was presented as a potential conflict of interest by watchdogs, there’s no evidence of wrongdoing or illegal activity on the part of either Biden when it comes to Ukraine.
According to witness testimony, Trump wanted the investigations to be publicly announced, but wasn’t all that concerned that they were actually carried out to root out supposed corruption. In short, Trump seemingly wanted to drag Biden’s name through the mud ahead of the 2020 election.
But congressional Republicans and the president’s defense team have claimed there’s no case against Trump. Instead of engaging with the substance of the allegations against Trump, they’ve blasted the process and spent much of their time zeroing in on baseless accusations against the Bidens — who were not on trial. They’ve also pointed to Zelensky stating there was “no pressure,” while leaving out the fact the Ukrainian president is extraordinarily reliant on US assistance and therefore highly unlikely to speak out against the president. 
Meanwhile, Republicans who have not lent their full-throated support to the relentless obfuscation have been ostracized.
Sen. Mitt Romney of Utah, the former GOP presidential nominee, was promptly declared disinvited from this year’s Conservative Political Action Conference (CPAC) after he voted in favor of calling witnesses. “The ‘extreme conservative’ and Junior Senator from the great state of Utah, @SenatorRomney is formally NOT invited to #CPAC2020,” tweeted Matt Schlapp, an organizer of the annual conservative conference.
Romney and Sen. Susan Collins were the only two Republicans who voted to call for witnesses. 
Trump’s impeachment trial was in many ways more a loyalty test for Senate Republicans than a thoughtful examination of serious allegations against a sitting president. Democratic Rep. Adam Schiff, the lead House impeachment manager, alluded to this in his closing remarks. 
—House Intelligence Committee (@HouseIntel) February 3, 2020
“What has changed? The short answer is: we have changed…For reasons as varied as the stars, the members of this body and ours are now far more accepting of the most serious misconduct of a president as long as it is a president of ones own party,” Schiff said.