There are some on the left who wish to incite violence and cause trouble - This is nothing new. The vast, vast majority of them, however, have zero intention of actively participating. They may (or may not) cheer when a glass window gets broken, but they won't be stooping to pick up a rock of their own.
For this reason, when push comes to shove, those who intend to do harm ultimately get crushed. For example:
https://philadelphia.cbslocal.com/2018/07/03/protests-turn-violent-as-demonstrators-arrested-in-front-of-philadelphia-ice-building/
All that ended up happening was about thirty arrested. No violent overthrow, no change in policy, no one seriously hurt.
Most people don't sympathize with these folks, which is why they feel the need to get violent. And the more they do this sort of thing, the more they are likely to repulse, not attract, supporters.
So fret not. Let them have their tantrum - That's how they lose.