There are also many people that go to the extremist views because they want to be different. They are guided by the mainstream and choose a different side, just so they can feel like a rebel. I don't really consider this independent thought.
Seemingly binary choices like abortion always have the third option of not caring. But again that’s the headline stance policy deals with complexity. If someone feels very late term abortion is an abomination but the morning after pill is fine they need to define where that border exists. The extreme end is something like banning condom usage. Side issues like aborting for genetic issues or birth defects further split the issue.
Taxes are about as far from a binary issue as it gets. Unless you abolish government they need to collect some money, so the real question is exactly how much money they want to collect and from whom. Hand all the different numbers to every American and there is a reasonable chance none of them would pick the same budget as was past last year.
The only reason that the person before you didn't include this view is because its outside of their overton window.
Anyway, take 10 issues that fall on exactly 2 sides, and you should never meet two people that agree with them all.
Actually, this right here is a stellar example of how political concerns and the vying of organizations for power warps the way we think about nuanced concepts on a fundamental level. It ends up the detailed, even-handed treatments make for poor slogans.