You are right that these Republicans have “no shame”, but the Democrats’ media presentation may have given them more than they bargained for. The Democrats’ presentation won’t convict Trump, but it could pull just enough Republicans (5 or 6) to vote for a censure with attached legislation to prevent Trump from running for office again by linking it to section 3 of the 14th Amendment. Ironically, the Republican Party might actually hope for this outcome because it would get rid of Trump without the majority of the party having to take a stand against him.
This strategy is actually politically possible and is explained near the end of The War After the Election [https://medium.com/illumination-curated/the-war-after-the-election-545de96aa4ca?source=friends_link&sk=627c55d616d9296af3e398f1686493a4] and in a six paragraph link at the end of it that explains the legislation.
The Republican Party itself must be held accountable in other ways afterwards.