A)That’s not true, remember Trump nearly carried Maine, a Republican could hold that Senate seat
B)Her seat is not up for election in 2018, if she were elected Governor she would resign just before taking office and get to appoint her successor
God forbid.
If she wins, either Collins herself of current Gov. LePage would appoint her successor, who would serve until a special election is held (which could come as late as Nov. 2020). Unless ME changes its law as AK did so that the governor has to wait a few days in order to fill a Senate vacancy, nothing would stop Gov. LePage from appointing the new Senator right after Collins resigns (and before she becomes governor). While I certainly trust LePage more than Collins to make a good appointment, I don’t think that states should allow lame ducks to make an appointment a few minutes before their terms end. For this reason, my preference would be that, should Collins win the governorship, she and Gov. LePage agree on the new senator (perhaps Congressman Poliquin, who is far more conservative than Collins, albeit not as conservative as LePage, and who probably would be our strongest candidate to hold the seat in 2020; he would be replaced in the House by the winner of a special election, who almost certainly will be a Republican (maybe LePage, if he wants it)), and have the Governor and Governor-elect announce it together.