Article I, §5, clause 2: “Each House may determine the Rules of its Proceedings, punish its Members for disorderly Behavior, and, with the Concurrence of two thirds, expel a member.”
I have not researched this, but as a lawyer my immediate reaction is that the disorderly behavior must occur while a senator in order for expulsion to be an option.
There may be something to that. For example.. “punish it’s members...” He’s not a member, nor is he allowed on the floor (if he wins) until he’s sworn in. And they could refuse to swear him in .
If he’s out of the Senate one way or another by Senate decision, the Senate could order a special election as they have done before? Or, could the Governor appoint a replacement for the vacancy as they normally do for vacancies? I don’t think Democrats would like that option.
And is there a Senate definition for disorderly behavior?
This whole situation is why we have lawyers.
As a lawyer, the RINOs, GOPe, and Rats will rule that for Democrats, the "disorderly behavior" for expulsion has to occur when he or she is member of the Senate. For Moore and other conservative, it means that expulsion applies if he or she shoplifted a fireball at six years old.
FYI -- Under current Senate rules expulsion requires an adjudicatory hearing where Moore should have an opportunity to present and cross-examine witnesses.