U.S. Senator Mitt Romney (R-UT) speaks to reporters on Capitol Hill in Washington, the United States, Jan. 19, 2021.

Erin Scott | Reuters

Senator Mitt Romney, R-Utah, said Sunday that the impeachment trial of former President Donald Trump in the Senate was constitutional and that Trump’s alleged involvement in the U.S. Capitol insurrection was a criminal offense.

Romney’s comments come after several Senate Republicans expressed their support for a controversial legal argument that conducting a Senate trial after a president leaves the country is unconstitutional.

“It’s pretty clear the efforts are constitutional,” Romney said during an interview on CNN. “I believe that what is alleged and what we have seen that provokes insurrection is a criminal offense. If not, what is it?”

Trump became the first U.S. President to be tried twice by Parliament after the Chamber charged him with high crimes and misdemeanors for instigating a riot in the U.S. Capitol on Jan. 6 that killed five people, including one Capitol Policeman.

A week after the uprising, 10 Republicans voted against Trump with all 222 Democrats. The impeachment proceedings against the Senate are due to begin in the week of February 8th.

The process begins Monday when the House files its impeachment article with the Senate. Senators will be sworn in as jurors on Tuesday.

The Senate will need 67 votes to condemn Trump. If all Democrats supported a condemnation, it would take 17 Republicans to join them. If the Senate condemns Trump, he could no longer become president in 2025.

The GOP Senators Lisa Murkowski from Alaska and Pat Toomey from Pennsylvania had asked Trump to resign. Kentucky Republican Senate Chairman Mitch McConnell told colleagues he had not yet made a decision on whether or not to vote in favor of condemning Trump.

Romney was the only Republican in the Senate who, along with the Democrats, attempted to remove the president from office in December 2019.

Trump was first charged with abuse of power and obstruction of Congress after pressuring Ukraine to investigate Joe Biden. The Republican-held Senate acquitted him.