McConnell has already said as much. There was a thread about it a couple of days ago. He was saying he doesn't see how they can overcome a filibuster. He may have the stones, but he certainly lacks the confidence and certainly does not inspire confidence in me when he says that attempts to repeal it will likely fail.
One of McConnell's problems is his RINOs. In the vote you are referring to, an attempt to rein in the EPA, the final tally was 56-42 -- four votes short of defeating the filibuster.
With 47 Republicans in the Senate, one would initially think that nine Democrats crossed over to vote with 'Pubbies. Actually, there were thirteen!.
Because four 'Pubbies crossed over and voted for the EPA -- Scott Brown (R-Ma), Susan Collins (R-Me), Olympia Snowe (R-Me) and Lamar Alexander (R-Tn).
If those four had stayed home, the GOP initiative would've succeeded.
One can legitimately criticize McConnell's leadership if he is unable to control his caucus.