Rand Paul is struggling. His SuperPAC pulled in very little, he's dropping in the polls, and he's not invited to the closed doors meetings with the mega-donors anymore.
He had a decent strategy in trying to keep most stances that his father had, but being a bit more hawkish. Unfortunately for him, it has turned out very poorly, as he's bled potential voters as he looks like a turncoat. Still plenty of time before Iowa/NH, but it isn't looking good for him.
As a Dem, I'm not sad to see him drift off. I think the only candidates that can beat Hillary are Bush, Rubio, and Paul.