In a decision thought to be reserved for Chuck Grassley, McConnell abruptly announces that Democratic senators will not be able to veto judicial nominees from their states. Photo: Chip Somodevilla/Getty Images

One of the big mysteries of 2017 has been whether Senate Judiciary Committee Chairman Chuck Grassley would stick to the practice (following that of his immediate Democratic predecessor, Pat Leahy) of letting the home-state senators of judicial nominees veto them, or bend to conservative pressure to let Donald Trump’s nominees go forward no matter what. As recently as mid-September, Grassley was expressing public ambivalence over the future of the so-called “blue slip” tradition (based on the century-old practice of home-state senators indicating approval or disapproval of proposed judges from their state via a blue piece of paper), which Republicans used aggressively to block Barack Obama’s judges. With Democratic Senator Al Franken asserting the right to veto a circuit-court judge from Minnesota, and both Democratic senators from Oregon objecting to another nominee from their state, push will soon come to shove.

But suddenly, it’s not Grassley but Senate Majority Leader Mitch McConnell announcing the demise of the “blue slip” tradition, via an interview with the Weekly Standard’s Fred Barnes:

“The majority” — that is, Republicans — will treat a blue slip “as simply notification of how you’re going to vote, not as an opportunity to blackball,” McConnell told me. The use of blue slips, he noted, is not a Senate rule and has “been honored in the breach over the years.” Now it won’t be honored at all.

It’s true, the blue-slip tradition isn’t all that hallowed. As ThinkProgress’s Ian Millhiser explained in a history of the practice, prior to Leahy and Grassley, only one Judiciary Committee chairman had followed a strict rule of letting one senator veto judicial nominees from his or her state; others gave some deference to home-state senators, but in varying degrees.

Still, there is considerable opportunism involved in exploiting the fullest version of blue-slip tradition when Barack Obama was president, and then abandoning it at just the right moment to let a Republican president fill all those vacancies created by GOP obstruction in the recent past.

But what’s most puzzling about McConnell’s announcement is that he, and not Chuck Grassley, is making it. Perhaps the Judiciary Committee chairman is deferring to his Leader so that the Kentuckian can get credit for clearing the way for Trump’s nominees; he could certainly use some political capital among the conservatives who are more often than not calling for his head. Maybe Grassley hadn’t made up his mind about blue slips, and McConnell decided to force the issue. Or quite possibly, Grassley’s not onboard with this step, and McConnell is lobbying him through the news media and the various conservative groups who will rush to applaud it.

We’ll know soon enough if this is the last word on blue slips, or just an important part of a continuing struggle. But the entire saga shows once again how large a priority Republicans, conservatives, and especially Christian conservatives place on reshaping the federal judiciary. By basically turning over his judicial nominating process to hard-core ideologues, Donald Trump has gone a long way toward overcoming the mistrust of Republican presidents among those whose primary focus is to reverse federal court precedents legalizing abortion and same-sex marriage, and allowing the expansion of the federal government at the expense of property owners. It is as crucial a part of his ability to maintain support among his base as anything he says or does on immigration or trade or race relations. Possibly under duress, Mitch McConnell is offering Trump a big assist on the judicial front. If it sticks, it will matter for a long, long time.