Though he often toes the line on conservative issues, Sen. Rand Paul isn’t afraid to move outside the Republican party’s comfort zone–a trait he shares with his father.

On Wednesday, Paul decried the effects of mandatory minimum sentences on minorities at a public hearing of Senate Judiciary Committee. MSNBC’s Lawrence O’Donnell called his testimony the “politically bravest thing said in Washington today.”

“If I told you that one out of three African-American males is forbidden by law from voting, you might think I was talking about Jim Crow 50 years ago,” Paul said. ”One-out-of-three African-American males are forbidden from voting because of the War on Drugs.”

Paul cited a recent ACLU report showing that though black males and white males use drugs in almost equal amounts, black makes are four times more likely to be convicted for it.

“Why are the arrest rates so lopsided? Because it’s frankly easier to go into urban areas and make arrests than it is to go into suburban areas,” Paul said.

The issue of mandatory minimum sentencing, and the racially biased outcomes of the War on Drugs, is something many Republicans won’t touch. In the Rewrite Monday, Lawrence O’Donnell called this kind of advocacy “Paulism,” something that sets both Ron Paul and Rand Paul apart from their GOP colleagues. It’s also a type of advocacy that may endanger the Paul family’s chances of attaining higher office.

“Rand Paul will never be on a Republican presidential ticket, not even in the vice-presidential slot, because Rand Paul, like his father before him, just says too many things that Republicans disagree with, especially conservative Republican primary voters,” O’Donnell said.

Recalling President Obama’s autobiography Dreams from my Father, Rand Paul said he’s “glad the president has such great compassion because he’s admitted, like a lot of other individuals who are now in elected office, that at one time he made mistakes as a youth. And I think, what a tragedy it would have been had he gone to prison. What a tragedy it would have been if America wouldn’t have gotten to see Barack Obama as a leader.”

O’Donnell seems to believe that this statement virtually disqualifies Paul as a presidential hopeful. “As soon as Ted Cruz heard that,” O’Donnell said, “he wrote in his head a 30-second attack ad against Rand Paul using that sentence: ‘What a tragedy it would have been if America wouldn’t have gotten to see Barack Obama as a leader.”’