Easy, Peasy...

[Cartaphelius]

Does Lindsey and McConnell, as they have done, declare and swear publicly
to violate the rule of law ingrained in the oath to uphold the Constitution
they made when seated as Senators as well as the oath they are required
to take during the impeachment, become any less guilty of High Crimes and/or
Misdemeanors?

By their sworn statement alone, they are immediately disqualified to render
judgement in the an impeached (criminal) Trump.

To consider another outcome but mandatory recusal would, in and of
itself be a violation of the rule of law.