HHS Secretary in the Cruz Administration or maybe Surgeon General. That’s pretty much it.
Admirable as it was, it's still a big leap from running the pediatric neurosurgery department at Johns Hopkins to running the US gov't.
Sen. Barbara Mikulski is up for reelection in 2016, and she'll be 80. I'd prefer to see him go for that job instead. I think he'd be a shoo-in. (Also, the red state senators could teach him about guns.)