The alt-right are just looking for a way to replay the Reichstag fire of 1933. For those who need a history refresher, after Hindenburg appointed Hitler chancellor (when the Nazis only had a plurality of seats in the Reichstag),  the Nazis burned down the parliament building and blamed it on the Communists. The plot involved an actual Communist who was persuaded to set the fire. The Communists were kicked out of the Reichstag, giving the Nazis the votes to pass the Enabling Act, which gave Hitler dictatorial powers. 
Today, some hotheads ( of various stripes) are all too willing to be the stooges of the alt-right by committing ridiculous and ineffective acts of violence that will provide the extreme right elements in the Trump administration with excuses to impose extraordinary measures. Trump must be resisted but violence just plays into his hands. Peaceful protest and civil disobedience is the only viable option.