Texas Rep. Ron Paul said it might be possible to impeach President Obama for the killing of Anwar al-Awlaki, the American-born cleric linked to al Qaeda killed in a drone strike Friday in Afghanistan.

Paul, who is running to replace Obama in 2012, told students at a University of New Hampshire town hall that an "impeachment process would be possible," according to multiple reports.

"You could do more investigating into this," he said. "I put responsibility on the president. This is obviously a major step in the wrong direction."

Paul, an outspoken libertarian, has been critical of the killing, arguing that the Obama administration operated in an extraconstitutional way in targeting Awlaki without having provided the cleric an opportunity for trial.

"No, I don't think that's a good way to deal with our problems," Paul said Friday. "He was born here, al-Awlaki was born here, he is an American citizen. He was never tried or charged for any crimes. No one knows if he killed anybody. We know he might have been associated with the underwear bomber [Umar Farouk Abdulmutallab].

"But if the American people accept this blindly and casually that we now have an accepted practice of the president assassinating people who he thinks are bad guys, I think it's sad."

This was not the first time Paul has suggested that Obama could face impeachment proceedings. Asked in June whether the president's decision to undertake military action in Libya without congressional approval constituted an impeachable offense, Paul agreed.

But presidential candidate said that his position should not be particularly shocking — he said that he would vote for impeachment against every president he's known.

"I just said almost every president I've known I'd probably have to vote for impeachment, because there's very little respect for the Constitution — and certainly there's no respect for the Constitution for assassinating American citizens," Paul said.