Increasingly used label for a core group of liberals who call talk shows and write letters to the editor pretending to be Republicans. A method of trolling popular among left-wing Democrats who believe conservative Republicans are all gun-totin, Bible-thumpin, inbred monobrows who won't detect the fact they are being trolled.
Crypto-liberals will claim they used to be Republicans, back when 'all Republicans were moderates', i.e., before the Tea Party "took over".
Caller: "Yep, we Republicans invented nationalized health care, but the Teabaggers took over, but I still consider myself a Republican."
Hannity: Get off the Phone, yer a crypto-liberal.
Steve: "Naw, Urban Dictionary won't accept 'Crypto-liberal'...they're too politically correct."
Bob: "That's true...they hate those right wing Bible-thumpers."