This is something you see often nowadays, especially on social media. Activists get some controversial policy approved, or censor some already-existing content. Yet if you protest it, you get the "dude why do you care" fence-sitters. They'll tell you that it doesn't matter that much and that both sides are silly anyway. Often these people are in complete support of said policy/censorship, but if you point it out they'll just tell you that those extremists don't represent them (because they're the enlightened "centrists", of course), and you get nowhere.
I feel like this is a big problem. How do you deal with this?
Usually I literally just link to them stories about the Left's pedo-fascination. Link to them stories about how they want to promote drag-queen story time, or how they want kids introduced to porn:
https://www1.cbn.com/cbnnews/entertainment/2021/may/drag-queen-story-hour-coming-into-homes-on-pbs-lets-learn-tv-series
https://kotakuinaction2.win/p/12jJGWbZVF/yes-kink-belongs-at-pride-and-i-/c/
Typically, it will put them on the defensive (because any normal person wouldn't want to be associated with such perversions). They won't change their mind, but the idea is to keep peppering them with stories and facts about the Left enabling or promoting child grooming.
Instead of them constantly chirping about "both sides", they'll want to distance themselves from the Left a bit, but just note that only "one side" wants that kind of facilitation.
It doesn't always work, but if you force them to defend a morally reprehensible position, they will defer to not wanting to be associated with that position. I haven't met one fence-sitter who changed their mind after such an exchange, HOWEVER... if it's in a public forum there have been other people who will see said information and get a bit of an eye-opener to how far gone the Left is.