Pro gay marriage in every poll in huge majorities
Pro marijuana legalization in huge majorities in every poll
Non Religious and or less religious
More friendly to Left economic policy and or social benefits (directly contradicting traditional Libertarian political thought)
Not arguing the particulars that you noted; just that I'd be hesitant to pigeonhole them as "liberal" if that means assuming they are committed to the Democrat party and all its planks and positions... they seem far less attached to party identity or ideology to me, and more concerned with getting what they want regardless of the political label normally attached to the position.
Just my thoughts and observations, as a middle-aged man who has been studying the rising teens-and-twentysomethings for some while now... they're a very different breed than Boomers or X/Y'ers. Less ideological and more pragmatic.
Fiddling While Rome Burns
Carthago Delenda Est
"I used to roll the dice; see the fear in my enemies' eyes... listen as the crowd would sing, 'now the old king is dead, Long Live the King.'.."
Just because the issue is settled doesn't stop the religious asshats and hate-mongers from whining about it and threatening to ignore the law.