Kentucky Sen. Rand Paul escalated an already-tense war of words with Arizona Sen. John McCain Thursday morning, by suggesting that it’s time for McCain to leave the Senate. McCain on Wednesday accused Paul of working for Russian President Vladimir Putin because he blocked a treaty that would allow Montenegro to join NATO. Paul dismissed that and fired back at McCain on MSNBC. You know, I think he makes a really, really strong case … for term limits, Paul said. I think maybe he’s past his prime. I think maybe he’s gotten a little unhinged. On Wednesday, McCain tried to call up the treaty on the floor of the Senate and said of anyone who blocked it, they are now carrying out the desires and ambitions of Vladimir Putin, and I do not say that lightly.