He was never a registered Democrat nor did he run as a Democrat. He's not even all that Liberal in a doctrinaire sense so it's difficult to cram him in under that label, and it would certainly be inapropriate to call him a RINO.
The current mayor, Bloomberg, was a big Democrat donor and ran as a Republican, then jumped out of the Republican label.
He's still a RINO ~ remember "once a RINO, forever a RINO".
He's also a Leftwingtard, and now he's even into treason peddling the powers of his political office to feather his financial nests in foreign countries, most particularly Moslem dominated foreign countries.
Nobody. Is. Going. To. Pay. Attention. To. Your. Distinctions.
When a RINO makes the news, he’s going to be called a RINO (by conservatives) and no one is going to go back to your playbook of terms-analysis and study the question of whether or not he’s “really” a RINO.
Why can’t you see that?