Oh sure, that way - voting against Johnson will ensure Dem control of the Senate - good idea ... We just got rid of a rabid Dem in that position, Russ Feingold. Want him back? He’d be glad to take the seat and continue his criminal schemes, should Johnston be primaried. There is no one that could win the election if Johnson is out, other than some Dem mentioned above.
What difference would it make? Swamp RINO or democrat? They both hate Trump but at least Democrats do something other than sit on their asses