Cannot touch Obama while he’s President. I’m a firm believer in that. You have to go through congress. If certain members of Congress become obstructionists, well find a rapid and sudden solution.
If there’s unequivocal proof of a president’s crime, I believe s/he could be arrested. Of course it was TV, but on an episode of ‘24’ a president was arrested when his wife got him to admit to his crimes on a concealed recording device.