[giantg2]

There's no fallacy here. I didn't mention the silent people. There are some. There does not appear to be a strong enough effect to have a noticeable difference in the ratios between the group with cognitive ability and those without.

[psychphysic]

You're making the same fallacy again thinking the sample you have of politically intolerant people represents the wider population.

Only 66% of Americans voted

That means 33% are likely highly politically tolerant. So tolerant they can't be bothered to vote.

Even if Intelegence and Political Tolerance had nearly perfect positive correlation you would expect even extremely intolerant people to show full spectrum of IQ and the converse.

Add on that, the discourse is dominated by the extremely intolerant and you get your claim.