Single-party voting is not necessarily irrational. A vote is a compromise. In a democracy, you need a majority to achieve anything, and with many options available, it's going to be rare for any single option to pass 50%. You get things done by making bargains with other voters. And those bargains have to be durable over time: I'll vote for your thing today if you'll vote for my thing tomorrow.

A party is a semi-formalized way of acknowledging those long-term bargains. They are sets of people with overlapping concerns -- sometimes distantly overlapping, where A and B have things in common, as do B and C, but A and C barely recognize each other. But if you can't get A, B, and C all to work together, none of them get what they want.

And in the worst case for them, X, Y, and Z achieve what they want instead -- positions that A, B, and C all agree are bad. The party that behaves with unity will get things that some of its members want and all members can live with. The party that has people opt out every time they disagree will achieve less-than-nothing.

The point is that a party can be a rational long-term decision even if it seems in conflict with short-term interests.

> a party can be a rational long-term decision

Only assuming that there is something like a constant ideology that party members adhere to over the decades.

Decades is too much to ask, but one decade isn't. It isn't a single ideology, but a set of overlapping ideologies. Those do shift, as circumstances and priorities change, but generally not radically within the scale of a single Presidential term.

I'd say it's not unreasonable to commit to a party and re-evaluate that commitment every decade (or perhaps 8 years is a better figure in the US). That's not to say that you won't be constantly looking out for new information, like a technological change that makes you reconsider your ideas or the discovery that some candidate is very untrustworthy. But if you want anything nontrivial done, it's not going to happen on a time frame shorter than a half-decade -- and your allies are going to want to believe that you'll still be with them once they've achieved your top priority.

> I'd say it's not unreasonable to commit to a party and re-evaluate that commitment every decade

But that's a rational attitude and not what I was describing initially.

A lot of people commit to a party for all their voting life which generally is quite a few decades. Sometimes this even goes for generations.

Oh, definitely. Parties change, and people's priorities change, and that gradually leads to a strain. Even purely rational people have a hard time telling when that strain has become a breach.

And a new alliance isn't easy to construct. You can't just go to the opposite party and say, "I've swung to you, so start catering to my priorities". Usually, you'll spend some time voting for nobody, in hopes that somebody will notice you, but that's hard without some level of organization, and that's work. In the meantime, you're failing to vote for a party that you had at least some sympathy for, and possibly losing to a party that has no reason to be on your side.

So a lot of people make party-line decisions based on inertia. They could improve their situation, but it's not as simple as changing their vote, since the existing alliances have priorities that won't change for a few votes. That leaves a lot of people in limbo, where there is no really great rational choice.

Hard to say what's 'rational' when voting. Lots of metrics; lots of theories. Vote for the person (character etc) vs their promises? Vote for the organization that will guide them (party) instead of the person?

I'd say its entirely irrational to vote for the program as outlined by the candidate speeches. Because they rarely happen.

It's not a problem with democracy. Its a problem with people and power.

> Hard to say what's 'rational' when voting

First step you examine all the available options objectively, like any other decision.

Do you think the majority of voters do that?

> I'd say its entirely irrational to vote for the program as outlined by the candidate speeches. Because they rarely happen.

Right, but this another problem altogether.

I'm getting some cynic vibes from your comment. Are you against voting?

I'm admitting I don't know what a rational voter looks like. I've been fooled too often by the campaigning so believe there's enough information there to make an 'informed' decision.

They vote ingroup first, whatever that means for them. What changed is that the're virtual ingroups these days, and that the limitations through location that once existed, where many connections just weren't possible, don't exist anymore.

> The biggest issue in democracy is that the majority of people vote irrationally.

That is to say, they don't vote in a manner consistent with how you perceive their interests.

I believe the term, when used in the literature, is more to mean "they don't vote in a manner consistent with how a dispassionate observer with access to global information state perceives the path to achieving their interests."

There's quite a lot of literature on the topic, and it's quite fascinating. For example, higher education has a tendency to change people's answers to a variety of survey questions (summary of this and other phenomena in the book https://en.wikipedia.org/wiki/The_Myth_of_the_Rational_Voter).

Voting irrationally is sequitur from "having interests", just not rational self-interests.

Having interests is not mutually exclusive to acting irrationally.

What you're saying is that people voting for the same party for 30 years, regardless of the political program, are satisfying their interests?

First of, I think you are confounding irrationality with being misinformed. The only irrational voters would be those who are clinically insane or similar. Secondly, it's not really much of an issue as such, as votes are aggregated and groups tend to act in an informed manner - c.f. wisdom of the crowds.