As best as I understand it, the Democratic Party will have to go to court, and if the court decides it before the ballots are printed she can still run as an independent.  If the court decides after the ballots are printed they will just post a notice at the polling places that she is not a Democrat.  Should be fun to watch the legal process, but that's just me.  Other's may want to take note if they fall into disfavor with the Dems,because the same process would be used against them as well.