> Your comparison to health care is telling. You make it seem like it's "rich" "party donors" who are opposed to single-payer healthcare. In reality, just 21% of the public supports abolishing private insurance (which single-payer healthcare necessarily would require).
Link to poll:
http://cdn.cnn.com/cnn/2019/images/07/01/rel8a.-.democrats.a...
Interviews were conducted from June 28-30, 2019 among a sample of 1,613 respondents. The landline total respondents were 565 and there were 1,048 cell phone respondents. The margin of sampling error for total respondents is +/- 3.0 at the 95% confidence level.
The actual question asked in this poll is:
Do you think the government should provide a national health insurance program for all Americans, even if this would require higher taxes?
56% responded yes.
Then:
And if the government instituted a national health insurance program for all Americans, do you think that program should or should not completely replace private health insurance?
Only 37% responded yes. That's where the 21% comes from. If you're curious how this broke down by demographic, it's on page 38 of the PDF.
But I want to point a couple things out. First, the OP didn't say anything about single-payer, and that's not the only model for universal healthcare. Second, I'm convinced this is largely a case of loss aversion, and the fact that results are skewed among those with private insurance out of ignorance of what their employer pays on their behalf. On loss aversion, just look at how public opinion changed on the ACA. Imagine asking 65+ year olds if they think Medicare should be abolished. Finally, even in the case of Medicare, there is supplemental private insurance. The way the polling question is asked would eliminate that. What American is going to respond yes to a question of the form "do you want to give up choice?"
> Maybe they don't want their FICA contributions to double or triple
How do you think a politician running on this proposal would fair? "We can lower your taxes by 15.3% but we're going to eliminate social security and Medicare."
Of course no one wants their FICA contributions to double or triple, or their taxes to go up in the abstract. And yet the existing entitlement programs are widely popular. Personally, I'd happily trade increased taxes for less uncertainty about paying for health care.
> There is a rhetorical tendency to blame American public policy on conspiracies rather than honestly attempting to figure out why people vote the way they do. ... Maybe Americans aren't irrational.
Here's an anecdotal example of what I think is probably a pretty representative rational American voter:
Caroline Penland, 44, a Republican, said she voted for Mr. Bishop. She is a reliable Republican voter, and a Christian who opposes abortion and favors “keeping God in schools.” She also favors some gun control, after being deeply affected by a 2012 shooting that occurred at the high school from which she graduated. But now, she said, was not a time to stray from the Republican fold. She voted for Mr. Trump and would do so again. “From an economical standpoint he’s doing really well,” she said. “First of all, he’s in my party. And I’m going to stick to my party right now,” Ms. Penland said of Mr. Bishop.
https://www.nytimes.com/2019/09/10/us/politics/north-carolin...
(I picked a Republican here because it was handy. There are equally "rational" Democrats and independents.)