Hmmm - well if I'm honest I couldn't offer you a good explanation of where socialism ends and Marxism begins so I'm not really qualified to say what he is or isn't.
I do think it's fair to say that in some cases power and the desire to retain it can soften your views. Could also be the other way around of course but I'm guessing that if they did gain power it wouldn't be quite as bad as I sometimes think it might be.
That's my only hope