As for Jesus, while he may have been peace-loving and anti-establishment (though it's hard to be more establishment than the Son of God), he was also a faith healer and exorcist who preached that The End Is Near, taught his followers to leave their families and normal lives to trek around Galilee and Judea with him, and picked fights with the reasonable, respectable religious leaders of his day. The Sadducees were roughly comparable to the Archbishop of Canterbury or the Chaplain of Harvard University; the Pharisees were liberals compared to them, if a bit hard-core -- think modern Congregationalists or Presbyterians. But if you want to put Jesus into a contemporary box, he was a radical, not a liberal. Within a few years of his death, his followers were speaking in tongues, like modern Pentecostals. That's not connected to Jesus in the gospels (except for a stray verse or two of doubtful authenticity), so we don't know where it came from.
Liberals don't like radicals. Radicals don't usually like liberals. They mock them for their readiness to sell out their fine principles as soon as the going gets rocky. It's a fair bet that if today's liberals had to deal with someone like the historical Jesus, they wouldn't actually call for his execution, but they'd find reasons not to work very hard to save his life either. As with Martin Luther King Jr., only after he was safely dead would liberals start squabbling with conservatives over who got to claim him for their side.
