President Trump is reportedly naming 10 nominees to federal courts on Monday — and, intriguingly, at least two of the people he's appointing are likely contenders for the Supreme Court in the future.

Per the New York Times’s Adam Liptak, the list of nominees includes Joan Larsen, a justice on the Michigan Supreme Court, who is nominated for the Sixth Circuit Court of Appeals; and Minnesota Supreme Court Justice David Stras, who is nominated for the Eighth Circuit. They were both featured on the two lists Trump’s campaign put out publicly during the 2016 election as potential nominees for the Supreme Court. The first list included only 11 names, and the second expanded it to 21, with one of the additions being Neil Gorsuch, whom Trump would indeed eventually pick for the Court.

Also on the second Supreme Court shortlist was Amul Thapar, a federal district court judge for the Eastern District of Kentucky. Trump nominated Thapar for the Sixth Circuit on March 21, in his only judicial appointment besides Gorsuch and the 10 new picks announced on Monday.

Trump is grooming picks for the Supreme Court

Larsen, Stras, and Thapar were all, at least in Trump’s view, qualified for the Supreme Court even though they haven’t yet served on a federal court of appeals. But picking them would have been unusual. The last Supreme Court nominee named directly from a district court post was Edward Terry Sanford in 1923; the last one named directly from a state’s Supreme Court was William Brennan in 1956. The vast majority of justices in the past half-century or so have come from federal courts of appeals.

Eight of the nine current justices were on a circuit court before being nominated for SCOTUS, and the exception, Elena Kagan, is only an exception because her appeals court nomination was blocked at the end of the Clinton administration. Sometimes nominees only spend a nominal amount of time on an appeals court before a Supreme Court promotion. John Roberts served barely two years on the DC Circuit before becoming chief justice; Clarence Thomas did about a year and a half on the same court. David Souter was on the First Circuit for a whopping two months before George H.W. Bush nominated him for SCOTUS.

By putting Larsen (who’s only 48), Stras (42), and Thapar (48) on appeals courts, Trump is further burnishing their credentials for future Supreme Court vacancies. All three of them, and especially Stras, will remain safely within the same age range as recent SCOTUS nominees for the next eight years; all of them would be able to serve, and would keep a seat in reliable conservative hands for up to three decades. They could even be appointed this same year, if a vacancy opens up, just as Souter was.

The most likely next vacancies are either Ruth Bader Ginsburg, an 84-year-old two-time cancer survivor who might need to retire for health reasons, and Anthony Kennedy, who’s now 80 and who former clerks told Reuters is pondering retirement this year or next, especially now that his former clerk Gorsuch is on the Court. Replacing either of them with Larsen, Stras, or Thapar would create a bloc of five solid conservatives (Roberts, Alito, Gorsuch, Thomas, and the new justice) who could consistently overrule the remaining liberal bloc.

Replacing Kennedy, who sometimes rules with Democrats on reproductive rights and LGBTQ issues but is otherwise fairly conservative, could provide the votes to end Roe v. Wade. And replacing Ginsburg, a thoroughgoing liberal, would move the Court to the right on a whole variety of issues.

These are down-the-line, doctrinaire conservative choices

Make no mistake: Larsen, Stras, and Thapar are all reliable conservatives. Larsen served in the Justice Department's Office of Legal Counsel in 2002-’03, when Jay Bybee and his deputy John Yoo were laying the groundwork for the Bush administration's torture regime. She also clerked for Antonin Scalia, and praised him in a eulogy for his conservative, textualist insistence that “statutes, cases and the Constitution were to be read for what they said, not for what the judges wished they would say.”

Stras's campaign site for reelection to the Minnesota Supreme Court stressed that he thought judges should "faithfully interpret and apply the Constitution and laws passed under the political process, not follow their own political leanings or personal preferences." Brian Fitzpatrick of Vanderbilt Law, who researches federal courts, told Bloomberg BNA that Thapar was "very Scalia-like and Thomas-like" in his jurisprudence.

And all three, tellingly, were included on Trump’s Supreme Court shortlist, which was compiled by the conservative Federalist Society’s Leonard Leo. Leo told the New Yorker’s Jeffrey Toobin in a profile earlier this year that abortion is "an act of force. It’s a threat to human life. It’s just that simple." His views on other jurisprudential matters are equally conservative. It’s hard to imagine him selecting anyone for Trump who doesn’t fit his standards, especially since Leo is famously well-connected and likely knows conservative judges’ views better than an observer just looking at their public opinions would.

Trump will have a lot of power to reshape the courts

There are currently 129 vacancies for federal courts of all types: 101 at district courts, 20 at courts of appeals, and eight at other specialty courts. There are now more than twice as many district and appeals court vacancies as when President Obama took office (as 13 have opened up since the above chart was made).

And as analysis from the team at Ballotpedia shows, the aging of the federal judiciary means that by the end of 2020, slightly over half of district and appeals court judgeships will be a) vacant, b) filled by Trump, or c) held by a judge old enough to take senior status and semi-retire, opening up the seat for another judge.

Not all of those judges will take senior status, of course. But some will. And regardless of how many do, the core point remains that Trump will have considerable power to use his Republican Senate majority, and the 50-vote threshold that Democrats established for lower court judgeships in 2013, to move the lower courts solidly to the right over the next four years. If he’s committed, and if he nominates people fast enough, there’s little that can stand in his way.

According to NYT’s Liptak, the 10 Monday nominees are expected to be part of "near monthly waves of nominations." If Trump keeps up this pace and no one else retires, then he'll have nominees for every vacant federal judgeship by May 2018. He could easily finish the process before midterm elections, and the 2018 Senate election map means it’s very unlikely those will end with Democrats retaking the body and slowing down confirmations.

This is a less visible way that Trump is remaking the federal government. But it’s hugely significant, including to the survival of Trump’s policy initiatives like the travel ban, and it’s a process that’s being guided less by him personally than by the broader conservative legal movement. If you ever wonder why rank-and-file Republican activists are tolerating this administration, this is a very good explanation.