How Established are Local Branches of German Parties?

I collected email addresses for an experiment, side benefit: I can tell something about local branches of German parties.

Dr. Merkel or: How the German Left Learned to Stop Worrying and Like the Chancellor

Have voters changed their evaluation of Angela Merkel during her 12 years in office? I find that Merkel has become more popular – especially among left-leaning partisans.