Maybe you could make a rational argument that he's center-right. Maybe. Trying to argue that he' s liberal is just a denial of every known bit of evidence out there. The fact that someone once was a liberal, or held liberal views, is not some sort of proof that they remain that forever. I can go position by position with you and lay out his conservative stances...but, of course, you'll just say he's faking it or lying. So your position is based in belief, not reason...and there's just no way to persuade "belief" by using facts and reason.
Here's some reason for you.
He backed two hard left NYC mayors
He spent his life as a full throated pro choicer.
He wants Planned parenthood funded
He is fine with trannies in ladies rooms and beauty pageants
He has supported gun control
He engaged in multiple instances of character assination forpolitical purposes
He donated large sums to both hard left politicians and the Clinton foundation.
I could go on, however the above historically documented FACT shows that yes, he is a liberal. What he says carries zero weight. History carries ALL the weight.