The announcement adds 20 names to those that Trump has already mentioned as potential picks, all of whom he said would be "jurists in the mold of Justices Antonin Scalia, Clarence Thomas and Samuel Alito."
The new list includes Republican Sens. Ted Cruz of Texas, Tom Cotton of Arkansas and Josh Hawley of Missouri, as well as Kentucky Attorney General Daniel Cameron; Paul Clement, a prominent lawyer for conservative causes; and 4th Circuit Appeals Judge Allison Jones Rushing, who was confirmed in 2019 at age 37.
Trump is seeking to energize courts-focused Republican and evangelical voters less than two months before the election as polls show him trailing Democratic nominee Joe Biden nationally and in most swing states.
Trump released a similar list of prospective justices in 2016, which helped him rally right-leaning voters who were skeptical of his candidacy but wanted more conservative judges. Trump said in June that he would release a new list by Sept. 1; Republicans say the timing mattered less than the release of a list.
Moments after being added to Trump's list, Cotton wrote on Twitter, "It's time for Roe v. Wade to go." Cruz said he was "grateful for the president's confidence in me." Hawley told NBC News that he has been telling Trump "for weeks" that he is "not interested in the job."
Conservative advocates praised the list and predicted that it would help him win re-election.
"President Trump won an upset victory in 2016 in large part over a Supreme Court fight," said Mike Davis, a former aide to Sen. Chuck Grassley, R-Iowa, who founded the group Article III Project to fight for Trump's judicial nominees.
After taking office, Trump picked Neil Gorsuch from that list, and he was soon confirmed to the Supreme Court. In November 2017, Trump expanded the list to 25 names; the following year, he picked Brett Kavanaugh to replace the retiring Justice Anthony Kennedy.
Davis predicted that Trump's attempt to elevate the Supreme Court as a top issue in the 2020 election would "unite conservatives" and attract independents.
Biden's campaign has signaled that it won't release a similar short list before the election. Some progressives criticized Democrats for all but ignoring the judiciary at their convention.
"We look forward to Donald Trump releasing his tax returns in the spirit of his newfound appreciation for transparency," Biden spokesman TJ Ducklo said in response to the list's being released.
While the Supreme Court has been a bigger motivator for Republicans than Democrats in the past, that may be changing.
A Pew Research Center poll released last month found that Supreme Court appointments ranked third on the list of top issues for voters in general, with 66 percent of Biden supporters saying they were "very important" to their votes and 61 percent of Trump supporters saying the same.
Download the NBC News app for breaking news and politics
"Today's short list is a reminder that Trump will appoint more justices like Brett Kavanaugh, who remains historically unpopular and already has ruled against abortion rights, LGBTQ equality, and Dreamers," said Chris Kang, a co-founder and chief counsel of the progressive group Demand Justice.
"Meanwhile, Joe Biden has promised to nominate the first Black woman justice, who will uphold civil rights and civil liberties, and the Democratic Party has called for structural court reforms to undo the Republican damage to our judiciary," Kang said.
There is no vacancy on the Supreme Court, and none of the nine members has signaled an intention to retire. But the winner of the election could have a significant impact on the court.
Justice Ruth Bader Ginsburg, the leader of the liberal wing, is 87, and she said in July that she was battling a recurrence of cancer. Justice Stephen Breyer is 82. Four more justices are 65 or older.
The Republican-led Senate has confirmed more than 200 Trump-picked judges to federal courts, most of them young and conservative, cementing a legacy that is poised to outlast his presidency and reshape American law for generations.