Sen. Chuck Grassley Charles (Chuck) Ernest GrassleyCollins says she will vote 'no' on Supreme Court nominee before election The Hill's Morning Report - Sponsored by Facebook - Trump, GOP allies prepare for SCOTUS nomination this week Gardner signals support for taking up Supreme Court nominee this year MORE (R-Iowa) on Friday said it's unlikely President Trump Donald John TrumpOmar fires back at Trump over rally remarks: 'This is my country' Pelosi: Trump hurrying to fill SCOTUS seat so he can repeal ObamaCare Trump mocks Biden appearance, mask use ahead of first debate MORE and Senate Majority Leader Mitch McConnell Addison (Mitch) Mitchell McConnellPelosi: Trump hurrying to fill SCOTUS seat so he can repeal ObamaCare Senate GOP aims to confirm Trump court pick by Oct. 29: report Trump argues full Supreme Court needed to settle potential election disputes MORE (R-Ky.) would want to uphold an informal rule against Senate consideration of Supreme Court nominees in a presidential election year.

Grassley, the chairman of the Senate Judiciary Committee, said in an interview on Iowa Public Television's "Iowa Press" that he personally would abide by the so-called Biden Rule — named after former senator and Vice President Joe Biden Joe BidenOmar fires back at Trump over rally remarks: 'This is my country' Trump mocks Biden appearance, mask use ahead of first debate Trump attacks Omar for criticizing US: 'How did you do where you came from?' MORE — if a Supreme Court vacancy opened in 2020.

But asked if Trump would want to follow the precedent, Grassley said he would not.

ADVERTISEMENT

"I'd follow that. That would be just the 12 months, or let's say the 10 months, before the election 2020. No, he wouldn't agree with that," Grassley said of Trump.

Asked if McConnell would want to follow the rule, Grassley replied: "No, he would not agree with it."

Republicans invoked the "Biden Rule" in 2016, after then-President Obama nominated Merrick Garland Merrick Brian GarlandPelosi: Trump hurrying to fill SCOTUS seat so he can repeal ObamaCare Trump argues full Supreme Court needed to settle potential election disputes Michelle Obama and Jennifer Lopez exchange Ginsburg memories MORE to the Supreme Court. Garland never received a hearing in the Senate, because Republicans argued at the time that the next president should get to fill the vacant seat.

Democrats bitterly protested that Republicans were simply looking for an excuse to deny Obama a Supreme Court nominee that was rightfully his. To this day, they say the seat was "stolen."

Trump tapped Neil Gorsuch for the seat shortly after taking office. He was confirmed in April 2017, with only three Democrats backing his nomination.

Speculation has swirled over the past year that a sitting Supreme Court justice — widely rumored to be Justice Anthony Kennedy — could soon retire, creating another vacancy for Trump to fill.

In an interview with conservative radio host Hugh Hewitt on Thursday, Grassley said that, if there is a Supreme Court vacancy to fill, Republicans want to fill it before the November midterm elections.

"I just hope that if there is going to be a nominee, I hope it’s now or within two or three weeks, because we’ve got to get this done before the election," Grassley said.

"So my message to any one of the nine Supreme Court justices: If you’re thinking about quitting this year, do it yesterday."