Sen. Dean Heller (R-Nev.) said in a speech last week he believes Supreme Court Justice Anthony Kennedy will retire this summer, according to audio of the speech obtained by Politico.

"Kennedy is going to retire around sometime early summer," Heller said in the speech, according to Politico. "Which I'm hoping will get our base a little motivated because right now they're not very motivated. But I think a new Supreme Court justice will get them motivated."

Heller is facing a tough GOP primary challenge ahead of the 2018 midterm elections from Las Vegas businessman Danny Tarkanian.

Kennedy's possible retirement has been rumored for months.

Last June, multiple reports said Kennedy was considering announcing his retirement.

But the 80-year-old justice seemingly quashed those rumors in January when he hired four law clerks for the October term.

Kennedy, who was appointed to the court by President Reagan in 1988, is considered the most pivotal justice on the Supreme Court and is often known for casting the tie-breaking vote in contentious decisions.

While he's among the court's conservative justices, he has sided with his liberal colleagues at times, including on the court's 2015 decision in Obergefell v. Hodges, which legalized same-sex marriage nationwide.

If Kennedy were to retire, it would set up President Trump to fill a second Supreme Court seat after he nominated Neil Gorsuch last year to replace Antonin Scalia, who died in 2016, while President Obama was still in office.

Trump made the appointment of a new conservative justice to the court one of the main promises of his presidential campaign.