Lieberman On The "Obama-As-Commie" Bus

The senator thinks Kristol's smear from one sentence is "a good question." Then this on Obama:

He’s got some positions that are far to the left of me and I think mainstream America.

I'm curious as to what those positions might be. I presume an opposition to permanent occupation of Iraq is not now some function of Marxism. Tax rates at the Clinton levels? Cap-and-trade? What actually does Lieberman mean by this?