In blue, we have the US states that have a smaller population than Los Angeles County. This is an enlightening map in the context of the debate about whether or not the Electoral College should perhaps be abolished.
The issue people have with the EC is that it leads to unequal representation: it entails that the vote of a person in a low population state is weighed more heavily than the vote of a person in a high population state. Of course, constitutionally speaking, the states elect the president. The people of each state send Electors, who will vote for a presidential candidate on that state's behalf. Still, the people of the low population states still do get more 'elector per capita' than the people in high population states. They get more bang for their buck (or in this case, for their vote).
However.. if you simply get rid of the EC, every single election will be decided by California, New York, Texas and Florida. All campaigns will focus there, and the rest of the states will become largely meaningless (politically speaking). Generally speaking, only the interests of those four big states will be considered when political decisions are made. This is also very far from equal representation.
So whatever you do, it seems, the current system will be unfair. As far as I can tell, any real solution would require a more fundamental (indeed drastic) reform. There are only two solutions I can think of that would solve the issue of representation:
1. Cut up the states with large populations and merge the states with small populations. Considering that the USA's largest city by population (NYC) has c. 8,5 million inhabitants, and that such a city would be hard to divide into multiple states, this number would become the "state population standard" by default. NYC would become a city-state, and the rest of the USA would be re-organised into 37 other states, each with roughly 8,5 million inhabitants. Some would be small (centred on a big city), others would be vast and largely rural. Nevertheless, each would have roughly the same population, so the same representative weight, regardless of whether or not there's an EC.
2. Radically decentralise the USA, so that 90% of all political decisions are made on a state or local level. Have the federal government reduced to main (national) infrastructure, the FBI, the US Marshals, foreign affairs and the military. That way, the 'weight' of any given state simply becomes far less important, because nearly all of politics plays out within the states themselves.
Personally, I'd suggest combining the two above ideas. Radically decentralise and re-organise the states at the same time. Why? Because lots of states have both progressive (often urban, high population) areas and conservative (often rural, low population) areas. Consider coastal California and inland California, for instance. Separating these areas would, combined with decentralisation, mean that in every new state, the vast majority of the population would get exactly the politics they'd like. Los Angeles could be a wildly progressive place, while inland regions in northeastern California could be part of a completely separate conservative state. And because the USA would be very decentralised, none of this would have undue influence on the rest of the Union.
Perhaps there is some other, better way to cut this Gordian knot of representative imbalance, but if so, I've yet to find it. As far as I'm concerned, the best solution is to bring politics closer to home.