Former South Carolina Rep. Mark Sanford, who lost in a 2018 Republican primary after President Donald Trump endorsed his opponent, is contemplating challenging the president.

Sanford will make his decision about running for president over the next month, he told the Charleston Post and Courier Tuesday. He said his goal is to drive a conversation about the national debt and government spending.

“Sometimes in life you’ve got to say what you’ve got to say, whether there’s an audience or not for that message,” Sanford told the Post and Courier. “I feel convicted.”

Michigan Rep. Justin Amash, who recently declared his independence from the Republican party, expressed support for a Sanford presidential bid on Twitter Tuesday morning. Only one other Republican, former Massachusetts Gov. William Weld, has announced a primary challenge to Trump.

Sanford, a member of the Freedom Caucus when he was in Congress, became the second incumbent to lose in 2018. He’d been an outspoken critic of the president’s rhetoric and policy, and his primary opponent, state Rep. Katie Arrington, tried to use that against him in the 1st District. Late in the afternoon of the June primary, Trump tweeted that Sanford was “unhelpful to me in my campaign to MAGA.”