"You can't impeach a judge just because you disagree with their opinion," Grassley said in an interview Thursday.
Last week, Rep. Brandon Gill introduced impeachment articles against U.S. District Judge James Boasberg after he ordered flights deporting more than 250 illegal immigrants believed to be members of the Venezuelan gang Tren de Aragua halted and returned to the U.S.
Gill said judges ruling against Trump and his agenda are a threat to democracy. Trump has also called for Boasberg's impeachment.
Grassley said legislation that would restrict district-level federal judges from issuing nationwide injunctions is in the works. A hearing is set for April 2 to discuss "legislative solutions to the bipartisan problem of universal injunctions."