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.