Well, for me, it's a question of "would I prefer Garland, or the possibility of a Republican nominee with the certainty of a very very bad precedent?" And the bad precedent+possibility of getting another Scalia combine to make Garland ... much more attractive.

(You know, I used to respect the Republican party. But over the last decade, they've really worked to make the B5 quote in my icon ... scarily applicable to real life.)