They see the choice they have as being loyal to Trump or not being loyal to him. But they are wrong.
They took an oath when they became a senator, and took another as they sat down for this impeachment trial. The real choice they must make is whether to honor the oaths they took or violate those oaths.
Here is just a part of an excellent article by Greg Sargent in The Washington Post:
As Donald Trump’s impeachment trial gets underway, the choice GOP senators face is being wildly mischaracterized. We keep hearing that they must choose between sticking with the former president or opposing him — between showing “loyalty” to Trump or not showing loyalty to him. . . .
But that isn’t the choice GOP senators actually face, and describing this choice accurately is of paramount importance.
The real choice they face is not between sticking with Trump or going against him. Rather, it’s between sticking with Trump or remaining faithful to their oath of office, which requires them to defend the Constitution against those who would undermine or destroy it, and to the oath of impartiality they take as impeachment jurors.
Trump tried to overthrow U.S. democracy to keep himself in power illegitimately, first through corrupt legal efforts, then through nakedly extralegal means, and then by inciting intimidation and violence to disrupt the constitutionally designated process for securing the peaceful conclusion of free and fair elections.
Trump fully intended to subvert the constitutional process designating how our elections unfold, and intended this every step of the way. GOP senators cannot remain “loyal” to Trump without breaking their oaths to execute their public positions faithfully. . . .
Acquitting Trump means declaring that these known facts do not point to high crimes and misdemeanors.
Senators take an oath of office to “support and defend the Constitution.” When serving as impeachment jurors, they take another oath to “do impartial justice according to the Constitution.”
Corey Brettschneider, a constitutional scholar who focuses on the role of oaths of office in the constitutional scheme, says these two oaths complement one another.
“That second oath doesn’t replace the first,” Brettschneider tells me. “It clarifies it.”
In acting as jurors, Brettschneider says, senators are supposed to answer “the specific question” of whether the president is guilty of “high crimes and misdemeanors.”
“Trump tried to subvert a free and fair election by spreading disinformation, trying to force public officials to overturn the results and riling his supporters up to attack the Capitol,” Brettschneider continued. “That is about as paradigmatic a high crime as one can get.”
When senators are in the role of jurors, Brettschneider continues, the two oaths interlock to set the terms of their “constitutional duty,” which precludes operating out of “partisan loyalty to a president.”
In other words, it’s either the former or the latter. The choice is not just about whether they are going to be “loyal” to Trump or not. That idea actually undersells the extraordinary dereliction of duty GOP senators will be committing if and when they vote to acquit.