To be fair to em2 (why?), the original comment seemed to be more that half of the people in the US have ideas that we (OO) don't take into account, and that we're blind because of it. He'd be right if we were actually unaware of those numbers and views, but we're not. We're well aware. We have looked at those ideas, and the claims made by those who hold them, and found them wanting. Many of them we've found to be unworthy of actually engaging with. Anti-vax, anti-science, racism, election denial, conspiracy theories - none of them are worth the pixels they're printed on. They're not based on reason, so reasonable discussion is impossible. They're not based on evidence or facts, so evidence and facts are irrelevant. They're willful delusion, and there's no counter-argument to them that won't be ignored (Fake news! Deep state! Q said so!), so other than trying to spread good information to keep them from spreading, why would we treat them seriously, except as a threat?
Most of the holders of those views just don't make any difference when it comes to voting (as you said.) I know that I've only had one election in the last twenty years where the candidate I voted for actually won. In that, my vote - and my opinion - don't matter. I'll never shift the balance away from the rednecks, the racists, and the people who want to roll things back to the 1950s.