Who would be more likely to switch parties, Collins or Murkowski?

[Jeppe]

Say that the Democrats and Republicans are 50-50 in the US Senate after the 2018 midterm elections. If the Democrats managed to successfully lobby a Republican Senator into defecting and joining the Democratic caucus, who would that be?

Murkowski is not up for re-election in 2024, and has won as an independent candidate before, but Collins is from a blue state and could lose the Democratic primary in 2020 a la Arlen Spector. Who is more likely to defect to give the Democrats a Senate majority?

[Oryxslayer]

If something like this were to happen it would be Collins switching to a D-caucusing Indie, the kind Maine seems to really love. But neither of these situations are likely.

[ursulahx]

Neither will happen. If either of these things were going to happen, they would have happened this year.

[GeorgiaModerate]

Neither will happen. If either of these things were going to happen, they would have happened this year.

Why would they happen this year?  Even if they both switched, the GOP would still control the Senate with Pence's tie-breaking vote.  There's no huge incentive for a senator to switch in this situation. 

The OP's scenario was a tied Senate after the midterms, when one switch would flip control.  In that case, the flipping senator would have a great deal of leverage, as Jim Jeffords did in 2001.

[Orser67]

I would say Murkowski, because I think Collins will probably seek re-nomination in 2020, whereas Murkowski isn't up for re-election until 2022 and has already shown that she can win without the Republican nomination.

[cvparty]

Neither will happen. If either of these things were going to happen, they would have happened this year.

the question isn't which will switch, it's which would be more likely to

[Dr. MB]

If anything it would be to independent, like Jim Jeffords.

[America Needs a 13-6 Progressive SCOTUS]

Collins