The party swarming with marketeers and pollsters during the 2015 election campaign was the lefty's Liberals.  They even had the help of the Obama Democrats' polling pros to tell them what promises would attract the real me firsters - people with their snouts buried deeply in the public trough.

As to his "inner Hitler", it is well established that the far left and the far right loons are much closer to each other in self righteous, authoritarian, black and white mind sets than they are to the folks in the broad political middle ground.   So yes this poster is likely channeling his inner Hitler (or Mao).

In recent years the far left has been more successful in intimidating and silencing dissent than the far right has been.  

Partly, this is because the left has convinced more people that fascist repression and suppression  can only be a right wing thing while the left's suppression is in the "noble cause" of political correctness.

Finally normal people have had enough of this con.