Former Oklahoma Senator Tom Coburn, a longtime conservative champion in the Senate, is endorsing Sen. Marco Rubio for president.

“Marco is the only candidate in this race who is in the mold of President Reagan,” Coburn said. “While some are offering a message of victimization and helplessness against Washington, Marco understands that ‘We the People’ are the establishment and the elites in American society.”

Coburn’s endorsement is arguably one of the biggest in the conservative movement, after a long career of fighting earmarks and runaway spending. He frequently lectured the Senate for racking up the national debt at the expense of future generations.

The former Senator included a stern repudiation of Donald Trump in his statement, warning the billionaire’s campaign is changing the face of the Republican party.

“Donald Trump’s campaign is a fabrication. He is perpetuating a fraud on the American people,” he said. “His empty promises, bullying and bloviating rhetoric will only deepen the frustration and disillusionment that gave rise to his campaign. He simply lacks the character, skills and policy knowledge to turn his grandiose promises into reality.”

Rubio will be rallying in Oklahoma later today as he crisscrosses the country in preparation for Super Tuesday.

Coburn argued strongly against Trump’s candidacy, warning conservatives that it “threatens to undo and reverse years of work” by the movement beginning with Goldwater and Reagan as well as the Gingrich revolution and the Tea Party.

“Put simply, Donald Trump has no plan to make America great again. He is a populist without portfolio,” he said.