Critics of Donald Trump make much of the fact that his legacy will forever bear the stain of impeachment, whatever the outcome of the prospective Senate trial next month.

But Trump is positioned to bequeath a much more substantial legacy, one that progressive activists and civil rights advocates warn will harm the cause of equality in the United States for decades to come.

That legacy is a judiciary remade deeply conservative in Trump’s own image. In securing the confirmation of his 50th appeals court judge earlier this month, Trump cemented his status as the most accomplished sponsor of federal judges in the modern history of the presidency.

No president has secured so many important judgeships as quickly. Barack Obama managed to confirm only 55 appeals court judges – in eight years. Trump’s presidency is not yet three years old.

“Among conservatives, this is probably one of the biggest bright spots,” said Josh Blackman, a professor at the South Texas College of Law specializing in the supreme court and constitutional law. “Not all conservatives are happy with a lot of things Trump has done, but on judges he’s killing it. It’s an across-the-board success that we’ve seen in this area.”

With the US supreme court ruling in only a small fraction of federal cases each year, appellate and district court judges actually wield immense power over some of the most urgent issues in American life, from reproductive rights to voting rights to anti-discrimination protections and action on the climate crisis.

Carl Tobias, a professor at Richmond School of Law specializing in federal judicial selection, called Trump’s performance on judges – with the notable assistance of the Senate majority leader, Mitch McConnell, and outside groups such as the Federalist Society – “an amazing accomplishment”.

“He has really made an imprint on the federal appeals courts,” said Tobias. “About a quarter of the active judges by now have been appointed by him. And that’s really substantial.”

Trump continued to run up the score on judges until the last minutes of the congressional calendar year. As the House debated impeachment, the Senate went to work on a final 13 Trump nominees to serve on district courts, one level below the appellate courts.

With a dozen confirmations last Thursday alone, Trump hit an end-of-year tally of 133 district court judges out of 677 total, 50 appeals court judges out of 179 total, and two US supreme court justices out of nine total.

People should be deeply troubled and scared as to the status of their rights and liberties over the next three to four decades Daniel Goldberg

“While Democrats in the House wasted all their time this week on a partisan impeachment,” Vice-President Mike Pence tweeted jubilantly on Friday morning, “the Senate confirmed 13 new judges making that a total of 185 amazing judges picked by President @realDonaldTrump!”

Legal analysts have blasted Trump and McConnell for allowing an unprecedented number of nominees to advance who have staked out extreme philosophies or been flagged as unqualified by the American Bar Association (ABA), the country’s largest non-partisan coalition of lawyers.

Progressive activists additionally express alarm at the relative youth of many Trump nominees, who assume lifelong appointments upon confirmation.

“The American people should be deeply troubled and scared as to the status of their rights and liberties over the next three to four decades,” said Daniel Goldberg, legal director at the progressive Alliance For Justice.

“It’s critical that the next Democratic president prioritize the courts like never before. While Donald Trump has been able to get his judges confirmed, we have never seen progressives as galvanized on the court issue as they are now.”

The confirmation this month of Sarah Pitlyk to the district court in St Louis and Lawrence VanDyke to the 9th circuit court of appeals, both of whom were rated unqualified by the ABA, should give Americans cause for alarm, said Goldberg, whose group has produced the report Trump’s Attacks on Our Justice System.

Pitlyk “spent her career fighting IVF and surrogacy” and VanDyke “has spent his career fighting environmental protections, women’s rights and LGBTQ rights”, Goldberg said.

Trump’s work on the courts would not have been possible without the assistance of McConnell, who blocked Obama judicial nominees and then relaxed Senate rules to accelerate the installation of Trump nominees. Another key Trump partner in the effort is the Federalist Society, the conservative legal group that has vetted judicial candidates and spoon-fed them to the White House.

Blackman said that former Senate majority leader Harry Reid’s 2013 decision to take the so-called “nuclear option” and abolish a rule requiring 60 votes to approve federal judicial appointments – a decision that followed unprecedented stalling on judicial appointments by then minority leader McConnell – had made it easier to confirm judges with ideologies outside the mainstream.

“I think because the nuclear option is gone, you no longer have to appeal to 60, you can appeal to 50,” said Blackman. “And I think with that, you have less of a need to appeal to the moderates, so I definitely think the tilt of the nominees is definitely away from the center.”

Tobias said that Trump’s judicial record could help pave the way to his re-election.

“I think for many Republicans, who don’t agree with a number of the Trump policies, they are willing to tolerate that in order to influence the judiciary,” he said. “Especially Evangelical Christians, who are substantially responsible for his election.

“Issues like abortion, LGBTQ rights, religious freedom – the judges are being chosen to take a particular view on those issues.”