I'm a Californian who would support that because currently, my vote is pretty meaningless as it is. Democrats know they don't have to campaign, or indeed, take any action at all, to win a Californian vote. So they don't.
Meanwhile, the Republicans are running around promising to build a giant altar where illegal immigrants can be sacrificed to Jesus so he'll create american jerbs despite the actions of President Osama Bin Mecha-Satan.
I want to be able to say that I am unsatisfied with the Democrat party line, but even though I vote for Jill Stein, it's not going to disturb the election at all.
Furthermore, I don't like the concept that someone's vote is worth much, much more than mine. Some rural Ohioan, for instance, has probably ten or maybe a hundred times larger a share of electoral responsibility in presidential elections, apparently because farmers are just worth more than people who live in cities.
...If you base it on population, you shift the electoral power to primarily urban-dominated states, which are going to have a different ideological bent and different issues. Quite frankly, you blue-shift the entire contest, Texas notwithstanding. Which I'd be all for at the moment, but in the abstract it's a bad thing for the country...
Better-representing the desires of the majority of Americans is bad now?