The rats are leaving what they seem to think is a sinking ship. The rats are Republicans and the sinking ship is their convention in Cleveland this coming July.
In other words, whatever vile skulduggery the party oligarchs are coming up with to deny Trump the nomination, a lot of lower-level Republicans don't want any part of it. They don't want to get anywhere near what's going to happen at that convention and they don't want their fingerprints on it.
"Asked Tuesday if he'd attend the convention, former Florida Gov. Jeb Bush told CNN: "No."
(Okay, now that I can get, seeing as how poor Jeb thought Cleveland in July was going to be his coronation. But what if the RINOs draft him anyway after they steal the nomination from Donald Trump and sodomize Ted Cruz out of whatever deal he thinks he has with them.)
Yeah, sure, Kelly. Betcha wild horses couldn't drag you to Cleveland because you know that whatever happens there, it's going to stink to high heaven.