As long as Trump nominates some more-or-less conventional conservative judge, why would anyone expect Jeff Flake to help block the nomination?
and he shouldn't
Flake shouldn't have blocked Merrick Garland in 2016, if the truth be known. There was no reason Garland should not have been voted on; indeed, there was no reason Garland shouldn't have been confirmed.
The only way Jeff Flake was correct in whatever he did to block Merrick Garland is if you are willing to say (A) the SCOTUS is a partisan institution, and (B) you're OK with that. Citizens United was right-wing judicial activism, as was Bush v. Gore. Let's not kid ourselves. I never thought that Trump would be a modern day Herbert Hoover appointing a Louis Brandeis to the SCOTUS. Those days are over. The GOP is bound and determined to have no more David Souters any more than the Democrats wish for more Byron Whites.
The SCOTUS is a partisan institution. Let's be honest. Flake's just playing politics like everyone else.
I don’t disagree, but true SCOTUS becoming explicitly partisan is a major dent in institionalism in the USA
It's been partisan for a long time. Kennedy was the last vestige of a guy who could go across to the other side for major decisions. That's what makes his retirement so scary.
Not to mention Obama getting shafted for his pick. If Garland was on the Supreme Court, Kennedy's retirement would have been less significant. It would just be a President picking their successor and the balance of the court would remain mostly the same.