WATCH: GOP Sen. calls Trump ‘a hard dog to keep on the porch’ in reaction to Tillerson firing

Sen. John Kennedy (R-La.) was among the lawmakers on Capitol Hill startled by President Trump’s firing of Secretary of State Rex Tillerson on Tuesday, describing the president as “a hard dog to keep on the porch.”

“As we say in Louisiana, President Trump is a hard dog to keep on the porch — he's not a porch dog, he's a running dog,” Kennedy told a handful of reporters Tuesday.

Kennedy explained that the president "likes to do things his way, and sometimes he likes to make personnel changes.” 

“That's his prerogative. The president is entitled to decide from whom he will take advice,” Kennedy said.

Trump announced early Tuesday morning that the nominated CIA Director Mike Pompeo to replace Tillerson, a decision applauded by a handful of Republicans, including Sens. Lindsey Graham (S.C.), Mike Rounds (S.D.) and Jim Inhofe (Okla.). Others, however, expressed concern over the pick.

Sen. Bill Nelson (D-Fla.) called Pompeo, “very much a partisan,” adding that he thought Tillerson was treated poorly.

“It’s a terrible choice, and I think the way Secretary Tillerson has been treated is terrible, and it shows the chaos that is going on in this administration,” Nelson said.

Outgoing Republican Senator Jeff Flake (Ariz.) expressed concern over Tillerson’s departure, citing the State Department’s vacant positions as civil servants continue to leave without new hires to take their spot.

“At a time when we have a lot of a lot of negotiating to do, to have some of our key negotiators and diplomats hollowed out over there it’s a concern not just at the top level — the appointments — but the career folks, that's where I'm really seeing a disturbing trend,” Flake said in an interview.

Tillerson’s last day will be March 31. 

Click on the video above to hear the senators in their own words