Democrats are hardly on pristine ground here. Since the bipartisan (24 Republicans and 19 conservative Democrats) 1968 election-year filibuster of Abe Fortas and Homer Thornberry, there have been two efforts at filibusters of Supreme Court nominees, both by Democrats: against Samuel Alito and William Rehnquist. There’s some debate over whether the first of Rehnquist’s nominations can truly considered to have been filibustered: in 1971, Democrats denied that they were filibustering him, then defeated a Republican cloture motion (the 52-42 margin for cloture fell short of the 67 votes then required), but proceeded to allow an immediate vote. But in 1986, when he was nominated for Chief Justice, a cloture motion was filed to stop a Ted Kennedy filibuster, and passed 68-31, with sixteen Democrats voting for cloture and 31 against (Senators voting against cloture included Joe Biden, John Kerry, and Al Gore). A more organized effort, led by Kerry, was made to filibuster Alito. This time, cloture passed by a vote of 72-25, with Kerry, Kennedy and Biden now joined by Barack Obama, Hillary Clinton, Chuck Schumer, and Dick Durbin, among others, voting to filibuster Alito’s nomination.
The third and final avenue of attack is to complain that sure, the Senate has spiked nominees without a floor vote before, but they didn’t even give Garland a hearing. But this misunderstands the role and history of hearings. The Constitution says nothing about nomination hearings, which are a relatively modern innovation. No Supreme Court nomination received a public hearing until Louis Brandeis in 1916, and Harlan Fiske Stone in 1925 was the first nominee to appear and testify before the Senate. Harold Burton in 1945 was the last Justice confirmed without a hearing. (John Marshall Harlan II was denied a hearing when nominated after the midterm elections in 1954, although he returned, testified and was confirmed in the following Senate session in 1955.) And as any nominee (including Gorsuch) can tell you, Judiciary Committee hearings aren’t for the benefit of the nominee, they’re for the benefit of the Senators. In 2016, the Senate majority decided to leave the Scalia vacancy open, to be filled after an election they had only slim hopes of winning. No hearing would have persuaded anyone of anything. The Senate wastes enough time on pointless charades as it is.