Realistically, the only real way to deal with them is counter-protest, but that’s difficult since the right has completely taken over the direct action/protest field in the past 10 years, so it’s a question whether or not the left can organize anymore (unless things get really bad, like how Antifa was very active during Trump).
We can try to combat misinformation and propaganda on the media to try and prevent this from even happening or telling people that it’s all bullshit, but it’s not effective since many popular sources directly benefit from this misinformation (be it in clicks or political goals) and either turn a blind eye or purposefully spread it (notable instance being Twitter).
Unless some sort of magical fairy-tale leftist revolution happens where most people get rallied under class issues and inequality rather than race and shared bigotry, this will probably continue happening more and more.