Liberals have problems with non-whites who don't understand their place within the Dem party and society as a whole. Obama was acceptable because, even to them, he wasn't Hillary. Couple that with their attitude of "We can get this black guy to do our bidding" and you have their perfect candidate. This time around, there is no Hillary to defeat, there's only the Bernie bros and potentially Warren, so their need for a specific "type" of candidate is less identity politics necessary this time around.
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