and the interests of the vast majority of people in the US.

Such absolete feelings don't go together with rational thinking.

That's my take on it.

and I have met parents on the brink of disaster who are voting republican.
Nurses & teachers too.
These people are nothing short of brain-dead zombies.

Some days I simply chalk it up to them being absolute morons & other days it drives me up the wall.
I've educated them on SPECIFIC POLICIES which would affect their everyday lives and nothing gets past their blank eyeballs.

Morons, morons. They get what they deserve.
Unfortunately, they are dragging the rest of us down with them.

I'm not trying to make excuses for them but I can't otherwise explain some of the strict rigidity and resistance to change I see including changing their mind when they're confronted with the truth.

They don't want the government to get their pie. Any day now it could happen. The lottery makes millionaires all the time.

People in the situation you described can become stressed and looking for a villon and a hero. They choose a fantasy hero to identify with, see themselves, hope , and dream , in other words create an association with an image. Yes, It's all psychology that can be understood through watching the campaign process. Unfortunately, about have the population want to identify with the likes of the Romney / Ryans. They're kidding themselves.

During the time that Gore was in court in 2000, they were screaming for Democrats to be shot in the street like dogs. Screamed about people on welfare destroying the country. Had VA and PO health care and all kinds of perks.

One couple had two disabled kids in state care. His wife finally had enough of him railing about taxes, public workers and their unions, and said did he want to bring the kids home and try to pay for their care in his house?

He shut up after that, but still voted GOP. This was even before the Tea Party got going. Who knows what's happened now. And Fox News was on all the time at their house and listening to Rush, etc.

in the emergency room, that is the most costly and worst form of treatment for chronic conditions

It is also immoral not to take care of our uninsured

The question you are asking is why do people vote against their own interest. Most likely because their parents were republicans, and they believe the deception

That is the differences between Democrats and republicans today. If a Democrat does not like the position of its party, or the direction it is going, it will voice that opinion. A republican today will follow their party line like a flock of sheep

Even when you point it out to them, they just don't see it.

My father's like this He has a pretty damn decent retirement, because in addition to Social Security he has a pension, 100% paid insurance to cover what Medicare doesn't, and a few other small but nice to have lifetime perks. He has these BECAUSE he belonged to a union. Now, he rails against unions constantly. It's among the most glaring examples of cognitive dissonance I've ever seen up close. He didn't used to be like this, and I believe the change is because of the brainwashing of Fox News and Rush Limbaugh et al.