“The firings of multiple Inspectors General is unprecedented; doing so without good cause chills the independence essential to their purpose. It is a threat to accountable democracy and a fissure in the constitutional balance of power,” the Utah Republican tweeted.
Romney is the only Senate Republican who voted to convict Trump of abuse of power earlier this year.
Though Republicans have been mostly quiet about the firing, earlier in the day, Republican Sen. Chuck Grassley, a longtime proponent of inspectors general, expressed some concern about Trump’s rationale for firing Linick.
“As I’ve said before, Congress requires written reasons justifying an IG’s removal. A general lack of confidence simply is not sufficient detail to satisfy Congress,” Grassley said in a statement.
Late Saturday night, Maine Sen. Susan Collins also responded to the firing in a series of tweets that suggested Linick’s dismissal didn’t meet the standard required by law.
This story has been updated with additional developments.
CNN’s Jeremy Diamond, Zachary Cohen and Manu Raju contributed to this story.