BATON ROUGE, La. >> Republican Sen. Bill Cassidy of Louisiana joined Democrats in voting against ending Donald Trump’s impeachment trial today, a surprise reversal that Cassidy said was a response to the former president’s lawyers doing “a terrible job” of arguing their case.

Cassidy was among six Republican senators who sided with Democrats on the question of whether a former president can be tried after leaving office. The Louisiana senator’s position was a switch from January, when he voted to end the proceedings on the grounds that they were unconstitutional.

The vote drew swift criticism from Republicans in the senator’s deeply conservative state. But Cassidy said Trump’s attorneys didn’t make their case. While the Democrats’ impeachment managers were “focused, they were organized,” relying on precedent and legal scholars, Trump’s team “was disorganized, random, had nothing,” he said.

“They talked about many things, but they didn’t talk about the issue at hand,” Cassidy said after the vote.

Still, the senator said his decision to move ahead with the trial shouldn’t be taken as a sign he will later vote to convict the former president. In recent calls with reporters, including one this morning, Cassidy has refused to say whether he believes Trump committed an impeachable offense.

“I have not yet decided on how I will vote,” he said.

Trump is the first president to face impeachment charges after leaving office. The House accused him of inciting an insurrection for his role in the Jan 6. siege on the U.S. Capitol. Hundreds of rioters ransacked the building to try to stop the certification of Democrat Joe Biden’s victory, a domestic attack on the nation’s seat of government unlike any in its history. Five people died.

The Republican Party of Louisiana quickly issued a statement today criticizing Cassidy for his vote and praising Louisiana’s junior GOP senator, John Kennedy, for voting against moving ahead with the impeachment trial. The Louisiana GOP said it was “profoundly disappointed” by Cassidy’s vote.

“We feel that an impeachment trial of a private citizen is not only an unconstitutional act, but also an attack on the very foundation of American democracy, which will have far reaching and unforeseen consequences for our republic,” the party’s statement said.

Republican Rep. Mike Johnson of Louisiana said he was “surprised” by Cassidy’s vote and suggested it was causing a stir in their ruby red state.

“I have not spoken to him, but I can tell you a lot of people from back home are calling me about it right now,” Johnson said.

Cassidy won reelection this fall to a six-year term, giving him some time to make amends with his party. But he’s already received criticism for accepting the Electoral College vote for Biden and for acknowledging the Democratic president’s victory weeks ahead of many of his colleagues.

A local Republican women’s club sent Cassidy a letter in December telling him they felt “betrayed” after he declared Biden had won the presidential election.

Kennedy, who is up for reelection next year, has issued statements panning the impeachment trial as unconstitutional and calling it “a thinly veiled effort by the uber-elites in our country, who look down on most Americans, to denigrate further those people who chose to vote for President Trump and not vote for President Biden.”