WASHINGTON — President Trump, who counts his two Supreme Court appointments as among his greatest successes, on Wednesday issued a new list of 20 potential nominees to the court, reviving an issue he believes was a key to his victory four years ago as he faces a difficult re-election fight.
In 2016, similar lists helped persuade wary conservatives to support his unconventional candidacy, particularly because the death of Justice Antonin Scalia that February had created a pending vacancy. The new list, which included three senators and two former solicitors general, was issued although there is no current vacancy, suggesting that the move had at least partly political aims.
Mr. Trump now has about 40 potential nominees to choose among should a vacancy arise. Before listing the new candidates on Wednesday, he singled out three judges from earlier lists who are widely believed to remain front-runners: Amy Coney Barrett of the United States Court of Appeals for the Seventh Circuit, in Chicago; Thomas M. Hardiman of the Third Circuit, in Philadelphia; and William H. Pryor Jr. of the 11th Circuit, in Atlanta.
The new list included three Republican senators: Tom Cotton of Arkansas, Ted Cruz of Texas and Josh Hawley of Missouri. Over the nation’s history, it was not unusual for sitting senators to be named to the Supreme Court, though it has been almost half a century since a former senator sat on the court.
Mr. Hawley said he had told the president he was not interested in the job. “My principal role in this process, this latest process, was to state where I will begin with judicial nominees, which is asking where they are on Roe vs. Wade,” he said, referring to the 1973 decision that established a constitutional right to abortion.
“Roe v. Wade,” Mr. Hawley said, “is a window into a judge’s judicial philosophy.”
Mr. Cotton, for his part, made his position clear shortly after Mr. Trump spoke. “It’s time for Roe v. Wade to go,” he wrote on Twitter.
Mr. Cruz, also writing on Twitter, said he was honored to be considered.
The new list included lawyers who have worked at the White House and in the Justice Department, notably Noel J. Francisco, who recently stepped down as solicitor general, having defended many of Mr. Trump’s policies and programs before the justices; Paul D. Clement, who served as solicitor general in the George W. Bush administration; Steven Engel, a Justice Department official; and Kate Todd, a White House lawyer.
“Should there be another vacancy on the Supreme Court during my presidency, my nominee will come from the names I have shared with the American public,” Mr. Trump said.
The list also included a number of federal appeals court judges: Bridget Shelton Bade and Lawrence J.C. VanDyke of the Ninth Circuit, in San Francisco; Stuart Kyle Duncan and James C. Ho of the Fifth Circuit, in New Orleans; Allison Jones Rushing of the Fourth Circuit, in Richmond, Va.; Gregory G. Katsas of the District of Columbia Circuit; Barbara Lagoa of the 11th Circuit; and Peter J. Phipps of the Third Circuit.
All of his candidates, Mr. Trump said, were judicial conservatives in the mold of Justice Scalia and two current members of the court, Justices Clarence Thomas and Samuel A. Alito Jr.
Mr. Trump challenged his Democratic opponent, former Vice President Joseph R. Biden Jr., to release a similar list. “He knows the names are so extremely far left that they could never withstand public scrutiny or receive acceptance,” Mr. Trump said.
Mr. Trump’s lists, compiled with the help of conservative legal groups, have long been fluid. The first one, issued in May 2016, did not include Justice Neil M. Gorsuch, Mr. Trump’s first appointee, who was first named on a second list issued that September.
Justice Brett M. Kavanaugh, Mr. Trump’s second appointee, did not appear on either list and was not included until a third one was issued in 2017. Justice Kavanaugh succeeded Justice Anthony M. Kennedy, who retired in 2018.
Though there is no Supreme Court vacancy, the recurrence of Justice Ruth Bader Ginsburg’s cancer, which she announced in July, has raised the prospect of one. At 87, she is the oldest member of the current court.
There is little question that Senate Republicans would try to confirm a third Trump nominee even in the waning days of his first term. “Oh, we’d fill it,” Senator Mitch McConnell of Kentucky, the majority leader, said last year.
Senate Republicans took a different approach in 2016, refusing to consider the nomination of Judge Merrick B. Garland in the last year of President Barack Obama’s second term.
Mr. McConnell and his allies say the two situations are different. Where one party controls the Senate and the other the presidency, as in 2016, they say, vacancies should not be filled in a presidential election year. Where the same party controls both the Senate and presidency, they argue, confirmations may proceed.
Democrats say this is hairsplitting that threatens the legitimacy of the court. But they may have little practical power to stop a third Trump nominee after changes in Senate rules on filibusters on nominations. All it takes now is a majority vote to confirm judicial nominees.
Michael D. Shear and Emily Cochrane contributed reporting.