The Republicans are up in arms because Sen. Al Franken, MN-Dem has put a hold on the nomination of Judge David Stras to the Eighth Circuit Court because he considers him "too conservative". See Star Tribune, 2017-09-06 for more details.
I don't know what the beef the Republicans have with Franken. After all, they held up Obama's nominee for months in the hope of a Republican president appointing a Justice of the Supreme Court more to their liking. They held up Judge Merrick Garland's nomination to the Supreme Court from March until Donald Trump was inaugurated.
