Revealing a potentially contentious Republican chasm, Senate Judiciary Chairman Charles E. Grassley told Fox News on Tuesday night that if he still leads the committee in 2020 and a Supreme Court seat becomes vacant, the panel would not consider a nominee.

That could put the Iowa Republican at odds with Senate Majority Leader Mitch McConnell.

McConnell signaled last week that he could reverse himself and consider what would be a third high court nominee for President Donald Trump should a vacancy arise in 2020. The Kentucky Republican famously blocked President Barack Obama’s election-year nomination of Merrick Garland in 2016.

“You have to go back to 1880 to find the last time a Senate controlled by a party different from the president filled a vacancy on the Supreme Court that was created in the middle of a presidential election year,” McConnell said in his own Fox News interview. “That’s been the history,”

But, unlike in 2016, he left open the door.

“The answer to your question,” McConnell said, “is we will see if there’s a vacancy in 2020.”