Officially would be one question. I believe Senators have switched before.
Second question would be: will their practice nullify the Republican majority in the Senate?
You can count Graham and McCain out for votes that matter to us, so consider the Senate 50-50 with Pence being the tie-breaker. Manchin seems like he wants to play with us, so another factor.
There was Jumpin’ Jim Jeffords, and I believe Joe Lieberman switched from Dem to Ind. but still largely caucused with the RATS except for defense and Israel issues.