Mitch McConnell has been a U.S. senator for 31 years. In those three decades, he's waxed eloquent on the profound constitutional duty of the Senate to vote on presidents' judicial nominees—at least two dozen times, according to this review of the record.
That includes at least 13 times in which he invoked the idea or the phrase "up or down vote," as in:
"We need to recommit ourselves to the 200 year principle that in a
democracy an up-or-down vote should be given to a President’s judicial nominees. It is simple. It is fair. It has been that way for over 2 centuries. And it’s served us well."
He said that on April 14, 2005. A little more than one month later, he gave this impassioned speech on the floor:
"The stakes are high. The Constitution of the United States is at stake. Article 2, section 2 clearly provides the President and the President alone nominates judges. The Senate is merely empowered to give advice and consent, but our Democratic colleagues want to change the rules…. there would be the distinct possibility and in fact great likelihood, if this continues, that 41 Members of the Senate will dictate to the President of the United States who may be a member of the Supreme Court and other courts.We have made every effort to reach out and compromise, but our colleagues at least so far have refused. The only choice that remains is to hold a vote to reaffirm the traditions and precedents that have served this body so well for the last 214 years. Let us vote."
That's one of eight instances in which he invoked the constitutional duty of the Senate "set forth in Article II, Section 2, that the Senate as an institution as reflected by the will of the majority of its Members, render its advice and consent on the President’s nominees." On that one he added this nice little bit: "We put propriety over partisanship."
That was one of three times that he brought up partisanship. Here's a particularly apt one, considering his current blockade of a Supreme Court nominee:
"For the first time in history, a minority of Senators, on a repeated, partisan, and systematic basis, has prevented the Senate as a whole from discharging its constitutional obligation to provide advice and consent on judicial nominations."
Maybe because it's a majority of senators this time flat out refusing to fulfill their constitutional obligation to the highest court of the land, it's perfectly normal and acceptable. So the institution's deep and historical "tradition" that he talks about seven times, like this one ...
"By tradition, the President may consult with Senators. But the tradition of “consultation’’ does not transform individual Senators into co-presidents. We have elections for that, and President Bush has won the last two."
… doesn't count any more. Apparently elections that result in a Democratic president don't count, either.