> I think that most conservatives don't look to some distant point in the past, but the status quo now, or perhaps some time earlier in their lifetime. If you view all over your examples through this lens, the ambiguity is resolved.

Is it? So a 45 year old Democrat is a "conservative" for opposing abortion restrictions because Roe v. Wade was decided before they were born? Or would become one later in life as people born before the decision die out, just from the passage of time and no change in policy? Someone who wants to cut federal spending is a "liberal" because it has been this high a percentage of GDP as long as anyone currently alive can remember?

> If you don't agree with this view, what alternative do you propose? Are conservative and progressive values and interests random? What values inform the positions they take and how they change over time?

The terms themselves aren't very useful because they're poorly defined. Trade tariffs are an ancient idea that have been enacted and repealed more than once in living memory. Liberal or conservative? I'm not sure it even makes sense to ask the question. It's more like populist vs. globalist.

The one dimensional axis only comes about as a result of the two party system. So what you're really asking is where the positions of Democrats vs. Republicans come from, and then the answer is a lot more obvious. They're political coalitions.

Ask yourself what abortion has to do with minimum wage. Basically nothing, right? You can try to come up with some kind of justification, like maybe having fewer people competing for jobs would lead to higher wages. But then you would expect the pro-abortion party to be the anti-immigration party. Oops.

It's not a coherent philosophy. It's a patchwork coalition that yields enough support to have a majority in the legislature about half of the time.

They change when the math changes. For example, some combination of the falling cost of renewable energy and worldwide efforts to fight climate change are probably about to devastate the oil industry, a major Republican constituency. They're not just going to resign themselves to a permanent minority, they're going to find some way to get back to 50%.

That means either stealing some constituency from the Democrats or taking one of theirs off the table. They're in a decent position right now to take out the teachers unions through school choice programs, for example.

Then the Democrats have to decide whether to let them or fight. If they let them, their platform changes. They don't have to be subservient to the teachers unions anymore, which could have knock on effects for other positions they couldn't previously take because the unions didn't like them. In a lot of ways that helps them, and all it costs them is the votes they won't need if the Republicans simultaneously lose the oil industry.

If they fight there, the Republicans are forced to take some other constituency instead. Maybe they push harder with the economic populism that won them the rust belt in 2016, and take it from the Democrats permanently. That could be worse for Democrats than dissolving the teachers unions; those are some important swing states. The Democrats would then have to find a way to win them back or win some other states instead.

So one thing changes and you get a chain reaction that reshapes the positions of both of the parties. It's not ideology, it's pragmatism.