During a conference call with Iowa reporters, Grassley said that the Senate has a "responsibility" to consider the nominee chosen by the winner of the election.
"We have the same responsibility for Trump," Grassley said, adding that he would categorize Trump's potential nominees as "strict constructionists" as opposed to Clinton's preference for "judicial activists."
Grassley went on to cite his rationale for refusing to confirm President Barack Obama's nominee, Merrick Garland, to the Supreme Court.
He reiterated that he wants the next president to fill the seat left empty by the late Justice Antonin Scalia, but added that he would be open to working with whichever candidate wins in November: “If that new president happens to be Hillary, we can’t just simply stonewall."
On Monday, Sen. John McCain (R-AZ) said in a radio interview that congressional Republicans would be "united" against Clinton's Supreme Court nominee if she was elected.
His office later walked those comments back in a statement, saying that "of course" McCain would vote on any Supreme Court nominee put forward by the next president.