There are so many to choose from. However, I think Alastair Campbell, Nick Cohen, David Aaronovitch, EU Supergirl and that ridiculous Femi individual have to be up there, though.
I think Jorge is a classic example of being on the echo chamber of twitter does to one. He was always obviously wrong about everything, but on here he got plenty of pushback on his nonsense and it probably tempered his excesses. On there he almost only ever spouts his nonsense to people who agree with him, which has made him genuinely insufferable.