Politics is a short term game.  Democrat calls for unity will come shortly before the next midterms.  There is no value to doing this now.  They will be trying everything to hamstring Trump on every issue (aside from infinite support for Israel) in the short term.  

Note this is absolutely what their supporters want them to do. 

 I’m aware they’d never do this, still think they’d gain more support than they’d lose 🤷🏽‍♂️