In July the Supreme Court gave presidents immunity from criminal prosecution for their official actions, but that does not mean those actions are always lawful or constitutional. In the coming months and years, virtually all of the most extreme plans that Donald Trump has announced — using the military to deport immigrants, politicizing the Justice Department to go after his perceived enemies, refusing to spend money that has been appropriated by Congress, among many others — will be challenged in the federal courts. As happened during Mr. Trump’s first term, many of those plans are likely to be struck down by fair-minded judges and appeals courts if they exceed the president’s powers.

That’s why it’s so important that President Biden and Senate Democrats confirm as many judges as possible to the federal bench in the weeks before Republicans assume control of the Senate on Jan. 3, 2025. Every judgeship left open on that date will probably be filled by Mr. Trump, who in the coming four years is likely to exceed his first-term record of appointing extreme judges. Many of his appointees went on to limit the ability to vote, upend fundamental reproductive rights and reduce oversight and checks on the power of the executive branch.

When it comes to judicial appointments, the public often focuses its attention on the Supreme Court, even though that court’s makeup is largely the product of chance, given its small size and rare vacancies. (Mr. Trump appointed more justices in one term than Barack Obama did in two.) But the lower federal courts — especially the U.S. Courts of Appeals — are more important to most Americans’ daily lives because they serve as the final word in a vast majority of cases. The Supreme Court agrees to decide only a tiny fraction each year.

As a result, it matters greatly who these judges are and how they approach the law and the Constitution. In the past, many of the judges appointed by presidents have focused on protecting democratic rights, like voting and representation, and reinforcing democratic values, like political equality. That’s in stark contrast to the sorts of judges appointed by Mr. Trump, many of whom have espoused radical, ahistoric views and have issued rulings that seem aimed at expanding Republican power.

Mr. Trump appointed 228 district and circuit court judges, the most in four years by any president since Jimmy Carter and just under a third of the federal bench. A look at some of their actions shows how important it is for Mr. Biden and the Senate to counterbalance their influence.

Judge Aileen Cannon of Florida repeatedly ruled in Mr. Trump’s favor in the case of the documents he was accused of purloining from the White House, only to be reversed in scathing terms by an appeals court. She then shocked legal experts by overturning decades of legal precedents in throwing out the documents indictment against Mr. Trump, ruling that the Justice Department’s special counsel system was illegal.

Three judges on the U.S. Court of Appeals for the Fifth Circuit ruled in October that Mississippi was illegally counting mail ballots that arrived after Election Day — a ruling celebrated by Republican Party officials who have tried to shrink the electorate by limiting mail balloting. Mississippi is one of 18 states, along with the District of Columbia and Puerto Rico, that count late-arriving ballots if they are postmarked by Election Day, and the ruling could still have an effect on the Republican Party’s efforts to stop that practice.

Six of the 17 judges on that appeals court were appointed by Mr. Trump, making the circuit now the most conservative in the country, even to the point of producing skepticism and criticism by the Supreme Court, which reversed it eight times in last year’s term — more than any other circuit. Justice Brett Kavanaugh wrote that the circuit was taking the judiciary down an “uncharted path” in an abortion-related case, and Justice Amy Coney Barrett chastised the circuit for advancing a “startlingly broad” theory in a social media case.

Judge Matthew Kacsmaryk of Texas, one of the most openly anti-abortion judges on the federal bench, issued a ruling last year limiting access to the abortion drug mifepristone. The ruling was overturned by the Supreme Court. The same judge has also ruled that federal protections for L.G.B.T.Q. workers went too far and against a federal program giving teenagers access to contraception.

Mr. Trump was correct when he said in 2023 that he had “totally transformed the federal judiciary,” and his supporters are pushing him to go even further in his second term. In his first four years, he relied primarily on the Federalist Society, an establishment conservative group, to supply him with judicial nominations; this time, Republicans say, he will be taking names from ultraright groups like the Article III Project, which has pushed for some of the most extreme candidates, and the First Liberty Institute, which wants religion to play a far bigger role in public life.

Mr. Trump’s supporters have repeatedly made it clear they expect him to choose judges who agree with his expansive definition of executive power — “I have the right to do whatever I want as president,” he said in 2019 — and a new slate of his appointees in the lower courts is likely to find new ways to build on the Supreme Court’s grant of immunity and allow his dictates to become a new American reality.

We are having trouble retrieving the article content.

Please enable JavaScript in your browser settings.

Thank you for your patience while we verify access. If you are in Reader mode please exit and log into your Times account, or subscribe for all of The Times.

Thank you for your patience while we verify access.

Already a subscriber? Log in.

Want all of The Times? Subscribe.lucky7

• The
• lucky7
• Senate
• Should
• Leave