De Blasio should've brought a true Democrat to swear into office, instead this fraud is getting more opportunity to hijack the party.
For what purpose is he hijacking the party, you think?
For starters, Bernie Sanders was a official independent through most of his political career, running against the Democratic candidates, even forcing the state party to endorse him. When he entered the primary to run against Hillary Clinton he promised to stay within the party into congress. When Bernie candidacy ended at the convention, Bernie switched party affillation again, clouding up all the cash from the party and never giving it back to the DNC. Bernie and his cronies want to make primaries open, when it threatens the well-being of the party, as they force the party to pander non-Democratic voters. The primary fiasco is why all primaries should only be open to committed members of the party.
The party already has to pander to non-democratic voters. Ever heard of the General Election?
Also, closed primaries are highly undemocratic, as those who may vote for the Democrats (Independents, maybe even some Republicans) don't get a choice in who their preferred candidate is for the party they might support.
I don't know... With closed primaries, Trump might not be President right now.