The election after the National Popular Vote Interstate Compact goes into effect will be radically different from all other Presidential elections.
When do you honestly think that will be?
My quick google search shows those (states) that definitely support it are the ones with highest population centers.
In the first place, no person's vote for the winning candidate will be wasted, which will eliminate the primary reason for voter apathy.
I see that as your opinion. We disagree, and our disagreements would be based partially on speculation, and partially on information from this most recent election or past ones. I do think votes would be considered wasted before and after elections under popular vote only. And I do think it has everything to do with population centers (aka cities) and how that is easier to get the vote in at election time.
No person's vote will have unequal weight.
In theory yes. Every vote matters type rhetoric. But in reality, the population centers will decide who wins. Those living in rural areas where people are spread out across much land would be at a disadvantage strategically. Yes, their votes carry equal wait to any individual in any population center, but collectively across the entire land mass that is America, it would show up as all the blue (Dem) votes are highly concentrated - or at least did in this most recent election.
If for some reason all this is too much wording for you, then just skip to next point now. I'll just add to above point that if the Compact you are suggesting goes into effect, then in the next 1 to 3 cycles, I do see that favoring Dems. But after a period, conservatives would catch up, and manifest a population center where if you go live there, you'll benefit from being surrounded by a majority of Republicans and Republican way of life (whatever that means). It would be well known as such, and then come time of elections, that population center would look very red on an overview map of the U.S.
The candidates will not spend all of their time, money, attention and promises on the few battleground states.
It would be most of their time, money and attention on population centers. It would make far more sense to go speak to city A where 3 million Dems reside, than to go speak in rural center B where 20 Dems reside. The whole 'way of life' thing would be turned on it's ear.
Again, skip to next point if all these words are too much for you to wade through. But knowing that you missed what I'm about to say next in my previous post, I'll say it again here. Agricultural industry would take an enormous hit. How that looks exactly, I'm not sure. It would have to still be there for us to survive as a country. But the places where that is happening 'the old fashioned way' is the places where those people (the old fashioned producers) would be at disadvantage, if not America being at disadvantage. Their individual votes would carry equal weight to any individual in population centers. Yet, the land (read as American resources) that they live on, would be neglected to some degree, especially during campaign season (so every 4 years, for 1.5 years, those areas would matter less).
What would matter most to politicians is population centers. The ones that favor their party would strategically matter the most, and the ones that are against them, but likely have some of their voters in those 'enemy' areas, would matter at least a little bit. Those areas would matter more than the many rural areas spread across the entire America. Therefore, once the population center map is in full swing, things would flip big time. I do think there would be cities that are well known to offer a "Progressive way of life" along with others that offer a "Conservative way of life." And the politicians that emerge from those camps would be doing everything they can to bolster the needs and resources for those centers.
A million votes in, say, Arkansas will be as important as a million votes in Florida. And there will not be the possibility of the candidate who didn't win the national popular vote getting to be President.
I won't disagree with this, nor spend much time on it. You're thinking short term with such assertions. In the first couple election cycles, the outcome would likely go to the Dems, while Pubs play catch up with resetting the political map. I think you are ignoring or underplaying how much population centers would matter going forward. I think you are ignoring the impact this would have on rural life (and industry) in America.
Presidential candidates will not try to herd their supporters into "particular areas".
Nope, party leaders and all citizens paying attention to how things work under such a system, will. There will be those who think this is just a fad, just an experiment and not move into population centers for that reason alone. Also not move because crime will likely be far less than in heavily populated areas. Not move because some very much realize how valuable land is, while overwhelming majority (in the population centers) would be focussed on ideological ideas or resources that have less to do with land, and more to do with technological superiority.