Republican regions are not falling to pieces. They have lower cost of living and lower taxes.
And it's hard to find good-paying jobs in them. Public services are awful; the streets aren't exactly paved with gold.
The United States also has a majority of its states vote Republican. Democrats don't have very many states overall. In recent election cycles Republicans usually have between 30-35 states and Democrats usually have between 15-20 states.
That's because of demographics. Democrats tend to be concentrated in high-density areas and Republicans in low-density areas.
It is a very good thing that the founding fathers founded the electoral college because they didn't want small states to get outvoted by majority rule. It wouldn't be fair if Democrats won every election just because Democrat states tend to be more populated. The founding fathers knew this and everyone fighting against the electoral college needs a good history lesson, or they just don't care.
It's people that count, not arbitrary political boundaries.
The Founders weren't unified on very much, and they show it by what they put into the Constitution. They didn't see eye-to-eye on slavery, for instance, and that led to the 3/5 compromise of counting "other persons". Yes, that's the wording that they used. They also didn't see eye to eye on how the legislature was to be composed. Small-state delegations preferred by-state representation, the "New Jersey plan", while large-state delegations preferred by-population representation, the "Virginia plan". What they adopted was a compromise, the "Connecticut compromise".
The Electoral College was an afterthought, from being unable to decide how to elect the President. Congress? The states' governors? Southern delegations didn't like a popular-vote election because they didn't have many qualified citizens. The North was much better. They were also concerned about lots of regional favorites being candidates. So they decided on the Electoral College.
Some EC defenders portray it as some committee of political experts and wise people, but it isn't. It soon turned into what it has been for most of its history, a half-assed system of aggregated and weighted popular votes.
I must note that one thing that they seemed to agree on is dislike for political parties. The Constitution ignores them, and some Founders wernt on record as deploring them. But once the US Gov't went into action, the politicians started dividing up into parties. So much for that bit of idealism.