Hey great question! So as you alluded to with your reasonable guidelines comment, no one supports 100% free speech. For example, speech that encourages violence is often not protected. Even Republicans want to censor certain speech like queer expression or reproductive rights. Everyone thinks certain speech should be protected and other speech should not but we disagree over where that line should be.
Conservatives are flattening the debate when they claim they support unfettered free speech & all their opponents support censorship. It's a dog whistle, especially since they generally support far more censorship overall.