It real question is "Afraid of what?!"
From what I have read, these were mostly non-violent protests.
Long answer? They're not afraid. The anti-freedom pro-genocide right-wing crowd is in support of anti-Israel protests. Yes, anti-Israel protests, not "pro-Gaza protests", which would begin with destroying Hamas and freeing Palestinians. There are several reasons for this.
First up, the full-on white supremacist nazi crowd supports killing jews and naturally supports any anti-Israel movements, whatever form they take. Yes, they are real. Russia is lead by a Dugandist, for instance, who is very much a nazi by a different name.
Second, they can influence said movements. You won't hear a word about Assad or, say, Hong Kong in these movements. Assad in particular, who is a genocidal dictator right next door, and has received very, very little criticism from these 'save Palestinians' movements. These are, of course, because they are dictators who are approved of by the right-wing pro-genocide movements.
Third.. there are certain movements like the Moonites. Some people of influence, like General Flynn, want the end times to begin and believe this can be accomplished by moving as many Jews as possible to the middle east, and ensuring continual wars to be going on there forever. They support any movement that will allow for more war in the middle east, like the current crop of protests against Israel. They simultaneously support Hamas -and- extremist right-wing Israelite governments because they want war.
That third group is why the Republican controlled house of representatives specifically picked the bill providing arms for Israel to read. If they had picked one without that, they wouldn't be able to stir up protests against their own decisions. The members of the house who are these kind of fanatics voted in favor of the bill, while the outright Nazis like Gosar voted against it.