Minnesota’s David Stras is one of Trump’s Court of Appeals nominees who could get blocked by his state’s Democratic senators. Photo: Glen Stubbe/AP

Today, as expected, Donald Trump rolled out a batch of ten lower federal court appointments, including five for district courts and five for courts of appeal. The en masse appointments were likely designed to show some momentum in one of many personnel areas where the administration has been laggard. And it was certainly intended to reinforce the warm and cozy feeling many conservatives felt over Neil Gorsuch’s nomination and confirmation to a seat on the Supreme Court.

Best we can tell, the ten-pack of proposed new judges are carefully vetted conservatives. Two, in fact, were from Trump’s famous SCOTUS prospect lists: Minnesota Supreme Court Justice David Stras, nominated for the Eighth Circuit, and Michigan Supreme Court Justice Joan Larsen, nominated for the Sixth Circuit. These 40-something rising stars got the seal of approval from the Federalist Society and Heritage Foundation commissars who put together Trump’s two lists, a very important ingredient in the thawing of #NeverTrump sentiments on the right late in the 2016 campaign. And it’s clear the new batch is pleasing to the very conservative judicial activists who will be fighting for rapid Senate confirmation of these and other judges:

“When it comes to fulfilling his campaign promise to appoint strong, principled judges, Trump is knocking it out of the park,” said Carrie Severino, chief counsel of the conservative Judicial Crisis Network, which spent millions of dollars to help win Gorsuch’s confirmation.

But there is a cloud — a blue one, to be specific — over the conservative celebration of a judiciary more likely to side with corporations over consumers. With the judicial filibuster long gone (it was abolished for lower-court judicial nominations by Senate Democrats in 2013 and for SCOTUS nominees by Senate Republicans this year), the main obstacle to this and other steps toward remaking the federal judiciary is an obscure but very important Senate practice called the “blue slip.” It’s basically a tradition (honored to varying degrees in the past) whereby the chairman of the Senate Judiciary Committee refuses to move a nominee for the judiciary (or for a U.S. attorney or U.S. marshal position) unless her or his home-state senators agree to it by returning a blue piece of paper signaling assent. It obviously gives senators individually and collectively great leverage over a president’s judicial nominees — especially an opposite-party president’s nominees. And it is sometimes used less as a senatorial veto than as a negotiating tool by senators who want influence over the selection of judges.

Current Judiciary Committee Chairman Chuck Grassley, like his immediate Democratic predecessor Pat Leahy, has been a staunch defender of the blue slip tradition. But now that there is a Republican president appointing conservative judges, Grassley is about to come under unholy pressure to abandon or at least modify it. Conservative opinion-leader Hugh Hewitt launched the campaign to come in the Washington Post last month:

The blue slip isn’t a law, and it would be anathema to the framers. It’s a leftover of decades past, a means by which individual senators could control their region’s judicial future. The non-return of a blue slip should receive no weight, or at most a trigger of a few weeks’ delay so as for the “concerned” senator to assemble a package of his or her reasons for the Judiciary Committee to review. There is no reason in the Constitution or common sense that voters from Michigan, which went for Trump, closely divided Virginia or even deep-blue New York should be denied judges because they have two senators that don’t like Trump’s nominees.

You can just imagine Donald Trump going nuts on Twitter over the blue slip once he become aware of it. And that could happen sooner rather than later: Both Stras and Larsen are from states with two Democratic senators (all but one of the other appointees are from states with two Republican senators). Expect a hue and cry to begin soon about potential Democratic obstruction of these fine Constitution-loving jurists.

In the end, as was the case with the judicial filibuster, Grassley and other Republicans will have to decide whether their short-term interest abolishing the blue slip tradition outweighs their long-term interests in maintaining it for use against future Democratic presidents. And Democrats may figure out ways to use blue slips carefully and strategically to resist an ideological overhaul of the federal courts without unduly provoking Grassley. It could be a chess game with a lot of lifetime appointments at stake.