Because I don't want to damn him with praise so faint that it wouldn't take wet paint off a waterslide, I'll refrain from observing that Sen. Marco Rubio (R-Fla.) is our sanest elected official with an R after his name. I'll just say that he's come a long way. When Rubio was elected to the Senate in 2010, it was as a standard-bearer of Tea Party constitutionalism.