Donald Trump expressed frustration as his Supreme Court appointees failed to do his bidding on key rulings. He posted, "These are not the people I interviewed to serve on the United States Supreme Court." Although he helped create a conservative court, his nominees often blocked his major policy goals.

Donald Trump helped create the most conservative Supreme Court in generations by adding three justices to the bench during his first presidency. Now, as the court begins its new term on Monday, he appears to have buyer's remorse.

In recent months, Trump's nominees -- Justices Neil Gorsuch, Brett Kavanaugh and Amy Coney Barrett -- have given deciding votes in rulings blocking the president's attempts to limit mail-in voting, birthright citizenship and the independence of the Federal Reserve. Before that, the court struck down his marquee tariffs policy, with majority votes from two of his appointees.

"These are not the people I interviewed to serve on the United States Supreme Court, they are merely a shell of their original selves," he posted on social media, adding that the court would be remembered for having rendered "some of the most destructive, hurtful and damaging decisions in our Country's history".

Trump's frustration with his nominees comes as he has sought to stretch the bounds of presidential power. As the court prepares to rule on his policies this term, including major cases related to his immigration crackdown, their relationship may sour further.

Legal scholars say the president's expectations of his appointees were unrealistic. "Trump fundamentally misunderstood what a Supreme Court justice is," said Harvard law professor Noah Feldman. They do not conceive of the job as "doing the bidding of a president", he added. "And thank goodness because that's not the job."

Trump's quest to ensure a reliably conservative Supreme Court began before he was first elected president. On the campaign trail in 2016, he published lists of would-be nominees compiled with input from "highly respected conservatives".

When he tapped Gorsuch to fill his first vacancy, Trump described choosing a Supreme Court justice as "the most important decision a President of the United States can make".

His three nominees have had a hand in delivering some of the conservative legal movement's most decisive victories in decades, including overturning the constitutional right to abortion, expanding gun rights and curbing federal regulators' power.

"All of them are the kinds of nominees that the conservative legal movement has long wanted to put on the bench," said Derek Muller, law professor at Notre-Dame, where Barrett previously taught.

Trump's anger overshadows how successful his administration has been in the court. Last term, Gorsuch and Kavanaugh each sided with the government in six of seven argued cases directly involving the administration. Barrett did so in five of seven.

A similar pattern emerged on the court's emergency docket, where the justices handle time-sensitive requests without full briefing or oral arguments. Trump's nominees sided with his administration in the overwhelming majority of cases.

But some of their most consequential breaks with the president have come on issues of great importance to him, including tariffs and birthright citizenship.

Justin Burnworth, an assistant law professor at the University of Florida, said the three have remained "consistent conservatives". But he added: "The expectation for the Trump administration [is] just this rubber stamp -- and they didn't get that. So it feels like a failure."

Barrett, Trump's third Supreme Court nominee, has faced the lion's share of criticism from the president and his allies.

Conservative lawmakers and activists criticised her as a "DEI hire", called for her impeachment and suggested she was responsible for "sending our country to the grave" after she voted to uphold birthright citizenship. In July, Trump reposted a commentator saying her record demonstrates she's "clearly terrified of the left".

Yet Feldman said her rulings have tracked closely with the conservative legal thinking championed by the late justice Antonin Scalia.

"As the other conservatives have unsystematically deviated from conservative norms, with the goal of producing expedient outcomes, she is the justice most likely to stand up and say, 'No, that's not our theory. That's not how we apply the constitution'," Feldman said. "And so conservatives are mad at her."

Trump's frustration with his justices has raised questions about whether he could shift the way he chooses candidates for open seats on judicial benches.

During his first term, he relied heavily on the Federalist Society to help select 234 judges to stock courts across the US -- including the three Supreme Court justices.

But as his appointees began ruling against his efforts to expand presidential power, Trump last year lashed out at the conservative legal network for its "bad advice" on his judicial nominations.

Mike Davis, a lawyer and Trump ally who advises the president on judicial selection, said Trump picked his Supreme Court justices under "unique time and circumstances", when the Republicans had slim control of the Senate at the time.

The emphasis this time around is on "bold and fearless" judges, he said, meaning "justices who are going to follow the law, regardless of the political blowback they get from the left".

Trump may not get the chance to test a new approach at the Supreme Court, however. Samuel Alito, after months of speculation that he would retire, in August signalled that he plans to remain on the court for at least another term.

And if Democrats win control of the Senate in November, the president would have difficulty confirming another nominee.

"You have to play the hand you're dealt when you're picking these judges," Davis said. "If there was a nomination right now, President Trump could pick -- and the Senate would confirm -- a much more conservative justice than in his first term.

"After the election, that's probably going to be a different story."