(Bloomberg Politics) — Ben Carson, the retired neurosurgeon who has been lighting up conservative crowds across the country, called for the country to move in a "new direction" Thursday while pressing Republican lawmakers to propose a viable alternative to the Affordable Care Act before trying to repeal President Barack Obama's cornerstone domestic policy achievement.

"They need to grasp a health care alternative before they try and remove Obamacare if they really want to gain some traction," Carson told the crowd at the annual Conservative Political Action Conferencein National Harbor, Md. Carson has proposed a system of health savings accounts to cover most individual health care needs.

Carson, who has been hiring senior staff for a potential presidential run, ticked through a series of critiques of the current administration on domestic and foreign policy. He said radical Islam "threatens to destroy" the U.S., though he pointed to "the Shia in Iran" as "every bit as dangerous if not more dangerous" than the Islamic State.