I don’t have an answer but I have wondered the same. Serbia, Georgia and Türkiye have currently some very large pro-democracy demonstrations, but the USA hasn’t. What there is seems to be pretty small scale.

Maybe pro-democrat Americans don’t feel like their actions matter? Perhaps the opposition just isn’t that popular? Maybe the USA just didn’t have all that strong traditions of civil action to to begin with. At least when compared to countries lile Georgia or Serbia.