There’s good reason to be worried about going against Trump, given how popular he is among the Republican base. But I’d argue this explanation is at least somewhat incomplete.
A lot of GOP senators may be willing to vote with Trump because they aren’t against him. They, like their voters, may really like him and his policies or believe he didn’t commit an impeachable offense.
And by voting against conviction, these senators are ensuring that Trump is with the Republican Party for the foreseeable future.
Besides, if Republican senators were really worried about their future electoral ambitions, there are reasons to think many of them could survive a primary challenge even if they voted to convict.
— to www.cnn.com