Hillary Clinton on Monday called on Republican Sen. Chuck Grassley of Iowa to “step up and do his job,” just hours after he warned the former secretary of state that law enforcement was coming for her.

“He should hold a hearing, and he should schedule it as soon as the Senate returns from recess,” Clinton said during a campaign stop at the University of Wisconsin-Madison, referencing Grassley’s role as chairman of the Senate Judiciary Committee in the confirmation process for Supreme Court nominee Merrick Garland.