eeethe problem is that in a "fair" election California, Texas, New York, and Florida are the ones that matter. They represent the most important states from a population and economic perspective. But at the same time, if you pander to them the other 70% of the population and 50% of the economy would go to shit. You need something to make sure the people who don't actually matter that much don't get shafted
How can the majority in a popular vote be marginalised? They are going to win the vote. This argument means that New York and California right now should be about to face disaster because their candidate lost. But that's not going to happen is it?
What I don't understand is why people insist on framing the idea of one man one vote in terms of states. They simply cease to be the issue. Individuals will vote. They won't all continue to vote for the same party, the idea that just because a state has always solidly voted one way means that entire the populace of it would continue to do so is wrong.
Take California for example, solidly Democrat but in a popular vote system the Republican party would be highly motivated to start appealing to those voters. There are definitely already Republicans in California, and there will definitely be non-voters and Democrat voters that they can win. Party loyalties aren't absolute and voter loyalty is highly elastic. Republicans will start to target those voters, and it works vice versa in other places. It won't hurt either party, California is a highly populous state so there are huge numbers of Republican votes to gain and vice versa elsewhere.
Political parties don't target voters on the basis of left or right, they haven't done for decades. Right now parties completely ignore huge numbers of concerns of voters in states they can't win so they end up in highly polarised positions. The popular vote would change that, they would have to address the concerns that matter to every voter. They wouldn't be able to say things that piss off huge swathes of the population and expect to win so incredibly divisive campaigning would be much more difficult.
If in your example there is 70% of the population that one party ignores they are dead in the water, the competition will sweep them up and win. I also don't recognise the idea that people in cities have a set of interests that involves screwing both the rest of the country and it's economy. There isn't a massive urban/rural split, on the contrary politicians would be highly motivated to find policies that are beneficial to as many people as possible.
There is no reason to believe that some kind of demagogue will arise who will wreak havoc along those lines, we're talking about a bedtime story monster at this point.