In the summer she was pulling 4-5% in some states.
Stein is like your typical far-left protest vote, much like whipped cream, deflates at the slightest hint of pressure.
Jill is hardly far left, voting Green is not a "protest vote", and the deflation from 4%-5% to 1%-3% is due to the fear-induced voter-shaming phenomenon which occurs every four years (since 2000). As for the topic at hand, it's incredible how the "electable candidate" Clinton remains unable to wrap this up, even against a demagogue like Trump.