Senate Majority Leader Mitch McConnell (R-KY) would not commit on Sunday to blocking a Supreme Court nominee if a vacancy on the high court arose during the final year of President Donald Trump’s term.

In 2016, McConnell refused to formally consider President Barack Obama’s nominee, Merrick Garland, citing what he called a historical precedent to not confirm—or even consider—Supreme Court nominees in the final year of a president’s term in order to give voters a say on the issue. But he was noncommittal Sunday on how he would proceed if a vacancy is created on the high court during the heat of the 2020 presidential election.

“We’ll see whether there’s a vacancy in 2020,” McConnell said on Fox News Sunday, a day after the Senate confirmed Brett Kavanaugh to the Supreme Court in what McConnell described as one of his proudest moments in politics—one that cemented a conservative legacy on the court for a generation.

But McConnell also gave hints as to how he would handle a hypothetical Supreme Court nomination during the final year of Trump’s term. If Republicans retain control of the Senate after November’s elections, that would mean the sitting president and the Senate majority leader would still be of the same party—which was not the case in 2016, when Obama nominated Garland.

“If you have a Senate of a different party than the president, you don’t fill a vacancy created in a presidential year,” McConnell said.

But Fox News Sunday host Chris Wallace noted that McConnell appeared to be changing the standard by which he would not move to confirm a Supreme Court nominee in an election year, because McConnell had never before mentioned the idea of the president and the Senate leader being of different political parties.

“You have to go back to 1880 to find the last time a vacancy created in a presidential election year on the Supreme Court was confirmed by a Senate of a different party of a president,” McConnell said.

But the majority leader might soon be on a crash course with Sen. Lindsey Graham (R-SC), who could become chairman of the Senate Judiciary Committee in the next Congress. Graham said just last week that he would honor the Garland standard if there is an opening on the high court in 2020.