James Stewart NYT column:

So the question for the Republican Senate leadership now and over the next few months, as the likely outcome becomes even clearer, is stark: Would they prefer an Obama nominee who is expected to be moderate and will be likely to deliver at least some of their agenda, or one chosen by Mrs. Clinton who, with a Democratic Senate, would have virtually unfettered discretion to pick anyone she wants?

As i wrote last week:

But here’s a more extreme version of this scenario. Suppose Obama nominates a very strong candidate who is a moderate, like a Sri Srinivasan. Trump is the Republican nominee and Hillary Clinton the Democratic nominee.  Trump looks like he’s going to lose (or perhaps he already loses). Clinton signals she will nominate a liberal Scalia or second Brennan  (think Pam Karlan) after inauguration.  The Senate might even flip (or be about to flip after a lame duck) to Democrats, who can kill the filibuster.

In that scenario, it is completely in McConnell’s interest to allow a vote (and perhaps even vote for) the Obama nominee.  The alternative would be worse.