It raises the stakes from somebody probably gets their ass kicked to somebody probably dies. If you can't fight hand to hand, having a knife isn't going to make your situation any better. Especially if you're up against someone with martial arts training who has drilled disarming people thousands of times.

Edit: Then, even if you win the fight you might be facing manslaughter, 2nd degree murder, or attempted murder charges instead of assault or battery. Leftists who kill reactionaries will not recieve the lieniency or institutional support that white supremacists like Kyle Rittenhouse get.