WASHINGTON — The headline speakers at the Conservative Political Action Conference’s annual showcase, the Ronald Reagan Dinner, have historically been rising stars in the Republican Party — firebrand pundits, prominent activists, future presidential candidates.

Last month, it was Scott Pruitt, the administrator of the Environmental Protection Agency.

In the past year, Mr. Pruitt has emerged as a hero to President Trump’s supporters for his hand in rolling back environmental rules at an agency long disliked by farmers, the fossil fuel industry and the far right. And he has occasionally shocked his employees by criticizing the very agency he heads.

“It was an agency that was weaponized against certain sectors of the economy,” Mr. Pruitt said to applause at the Reagan dinner.

Now, people close to Mr. Pruitt say he is using his perch as Mr. Trump’s deregulatory czar to position himself for further political prominence — starting with a run for office in his home state of Oklahoma. He is widely viewed as a future candidate for senator or governor there, and Mr. Pruitt has made it known that if the president replaces his beleaguered attorney general, Jeff Sessions, he would be ready to step into the job.