A spokesman for Mitch McConnell said that the Senate should confirm judicial appointees through at least the summer. The cutoff for confirming judges in an election year, known as the “Thurmond Rule,” “doesn’t need to be June, especially because we’re so far behind on the legislative calendar,” he said.

Similarly, Senator Jeff Sessions (R-AL) said, “Let me say this about the Thurmond Rule. It is a myth. It does not exist. There is no reason for stopping the confirmation of judicial nominees in the second half of a year in which there is a presidential election.”

Even a Bush spokesperson said that the “only thing clear about the so-called ‘Thurmond Rule’ is that there is no such defined rule.”

Of course, all that was in 2008, when George W. Bush was the lame-duck president and Democrats controlled the Senate.

Now that it’s 2016, and the tables are turned, McConnell has said he’d be shocked, shocked if President Obama nominated a Supreme Court justice as late as February of his final year in office.

In fact, while there’s hypocrisy on both sides of the aisle, a review of recent history reveals more of it on the Republican side.

Let’s begin at the beginning. For 166 years, Supreme Court confirmations used to be a matter of course, with rare exceptions. In the 19th century, they usually took only a few days. The current process of Judiciary Committee hearings began only in 1955, in the wake of Brown v. Board of Education, with segregationists and other conservatives outraged at the “activist” Warren Court.

The custom of not confirming judges in a presidential election year began with the avowed segregationist Strom Thurmond, who opposed LBJ’s appointment of Abe Fortas as chief justice back in 1968. (Notice, by the way, the “Thurmond Rule” wasn’t even about filling a vacancy—it was about moving Fortas from associate to chief justice.)

Prior to that time, Supreme Court nominations in election years were par for the course. Justice Frank Murphy was nominated in 1940, Cardozo in 1932, Clarke and Brandeis in 1916, and Pitney in 1912.

But there were many reasons for conservatives to oppose Fortas. As an associate justice, he had maintained an unusually close relationship with LBJ (allegedly, Fortas helped write one of LBJ’s State of the Union speeches). There was a minor scandal involving speaking fees. There was Fortas’s religion—it was one thing to have a “Jewish seat” on the Supreme Court, but quite another to have a Jew as chief.

But mostly, it was ideology. Fortas was a full-fledged member of the Warren Court, extending due process rights to minors, and writing the opinion that effectively banned creationism from public schools.

The tactic worked. The Fortas appointment was withdrawn, and the position of chief justice has been held by a conservative for the last 46 years (Burger, Rehnquist, Roberts).

Since then, the “Thurmond Rule” has been understood as holding that lifetime appointments of all types should not be made in the final six months of a president’s term in office.

In practice, however, the “Thurmond Rule” could best be described as the “Sore Loser’s Rule,” since it is wielded by whichever party doesn’t hold the White House at the moment. In July 2004, Republican Sen. Orrin Hatch said there was no such thing. And Republican Sen. John Cornyn threatened in 2008 that if Democrats invoked the Thurmond Rule, Republicans would go nuclear: “We could require 60 votes on every single motion, bill, and procedural move before the Senate,” he said at the time.

Now, it’s the Republicans’ turn to invoke the rule, and Democrats’ turn to be outraged.

But some hypocrisy is more equal than others.

First, the Thurmond Rule has never been extended back this far. In 2008, Democrats didn’t invoke it until the late summer; Sen. Dianne Feinstein said it kicks in after the first party convention. It’s February now, and even the longest Supreme Court confirmation in history—that of Justice Brandeis, in 1916—took 125 days. (Brandeis was called a “radical” and bitterly opposed by conservatives, with anti-Semitism even more overt than Fortas later faced.) So this would be an unprecedented expansion of the “Rule.”

Second, the “Rule” has never been applied to Supreme Court vacancies. On the contrary, when President Reagan nominated Anthony Kennedy to the court, he was confirmed 97-0 on Feb. 3, 1988, with Sen. McConnell voting in favor.

Now, in fairness, Kennedy was nominated in November 1987, after the Bork-Ginsburg controversies had left the court with eight justices for five months—seven months counting Kennedy’s confirmation. It was arguably a special case. Moreover, Kennedy was a consensus nominee who has emerged as the swing vote over the last decade precisely because he votes equally with conservatives (as in Citizens United) and liberals (as in the same-sex marriage cases).

But if no justice were confirmed now, the vacancy would be even longer: 12 months at least.

Third, the statistics cut sharply against Republicans.

According to a detailed study by the Brookings Institute, the Senate has already slowed the pace of judicial confirmations to record levels. In the case of Reagan, Clinton, and Bush, confirmations didn’t slow until the second half of the presidents’ eighth year in office. In their seventh years, the Senate confirmed 23, 17, and 29 judges, respectively. In Obama’s seventh year? 10.

In other words, the two-term Republican presidents fared almost twice as well as the two-term Democrat presidents, with Obama faring the worst by far.

Moreover, the “Thurmond Rule” has rarely been applied with the orthodoxy Republicans now are claiming. An exhaustive 2008 report by the nonpartisan Congressional Research Service unearthed a gold mine of historical information that belies the current majority’s claims:

In 1980, the Republican-led Senate confirmed 10 out of 13 judges nominated by President Carter in September, with Sen. Thurmond himself coming under fire for trying to block some of them.

In October 1988, the Democratic-led Senate Judiciary Committee led by Joe Biden confirmed 11 out of 22 of Ronald Reagan’s judicial appointees. In October 1992, the same committee confirmed 11 of George H.W. Bush’s.

In 2000, the Republican-led Senate confirmed 31 of President Clinton’s 56 nominations. And the 2004 Senate (narrow Republican majority, Republican president) confirmed a whopping 80 percent of nominees—despite claims that the Democrat minority was obstructing them.

In 2008, a Brookings Institute review found that George W. Bush’s confirmation rate was 58 percent for circuit court nominations, 43 percent for district courts—in other words, roughly the same.

In short, until this one, an opposing-party Senate has never observed the Thurmond Rule. Not in 1980, not in 1988, not in 1992, not in 2000. There are typically slowdowns in confirmations, but never a standstill. And the rule has never been invoked before the summer, let alone before the cherry blossoms bloom. Perhaps unsurprisingly, we’re in new territory this year, and at new heights of hypocrisy.