Raise your hand if you know how the electoral college works. If you do and live in the United States, you're part of a small minority. For those who don't, here's a very brief civics lesson.
The general idea is that citizens of each state vote for representatives (electors) to a body (the electoral college) that selects the president, and the number of representatives each state gets for the electoral college is weighted, based on the number of senators plus representatives to Congress. As for how the representatives for a particular state votes, that's usually on a winner-take-all basis. In other words, if a candidate has more votes than the runner up in a state, all the state's representatives to the Electoral College vote for the winner. While this process usually results in the popular vote getter for the whole country winning the election, it doesn't always. The 2000 election is a good example of that. Because of the winner-take-all approach, in theory someone can win the 11 most populous states by one vote each, get crushed in the remaining 39 states, and still get elected president.
And yet, there is no requirement that a state have all its electors vote for the statewide winner. In 1972, Maine decided to have two of its electors vote for the statewide winner, with the other electors decided based on Congressional district. With Maine presently having four electoral votes, it's possible that Maine can vote 3-1 in the electoral college. In 1992, Nebraska (presently with six electoral votes) adopted what's known as the "Maine Method," and those two states are the only ones that do not follow the winner-take-all approach for their electors. Going back to the 2000 election, if Florida had also done this (and assuming no other state did), then Gore would have been elected president.
It seems so much more reasonable for the electoral votes to be assigned under the Maine Method that it seems a wonder that more states haven't adopted it. Actually, given the politics of getting laws changed, it's no wonder at all. If you've got a largely Democratic state, with its governor and state legislature majority Democrat, and most of its Congressional representatives the same, there's no incentive to change the state laws so that the Democrats lose electors to Republicans. And the same holds in reverse. Thus, generally speaking, about the only way to switch to this approach en masse would be at the federal level, where both Democrats and Republicans have something to both win and lose. I'm not sure, however, that even if there was the impetus, whether the change could be done by statute. If it had to be done by constitutional amendment, it would be much harder, given that it would need to go through all those state legislatures that aren't changing things right now.
The wrinkle to all this is that some Republicans in California are proposing an amendment to the California constitution that would adopt the Maine Method in California. The amendment, which can pass by a simple majority of voters, would bypass the legislature. California has by far the most electors in the country, and in recent years has voted Democrat in the presidential elections, by significant margins. But not all of California is Democrat. In the current Congress, 19 of its 53 seats in Congress are held by Republicans. Under the Maine Method, if only 15 of those districts voted Republican in a presidential election, California would shift from 55-0 to 40-15, i.e., from +55 for the Democrats to +25, a difference of 30. It's far more likely that Republicans would carry even more districts (according to the link above, Bush took 22 districts in 2004, so the "Maine Method" would have moved Kerry's net in the state from 55-0 to 33-22, a difference of 44, and made the count in Ohio irrelevant). As you can imagine, that would make a huge difference in the 538-seat electoral college, given Bush defeated Gore by only five electoral votes in 2000.
The Republican entities promoting the amendment contend that this change would cause candidates to pay more attention to California, but political scientists say it would have the opposite effect. That's because gerrymandering has created so many safe districts in the state that there won't be but a handful of districts in play. They say it would be far better for candidates to focus on states like Florida, with its 27 electoral votes all going to the winner, and a fairly even split of the electorate. But then again, no matter the assertions being made, as the numbers I pointed out above demonstrate, there's little doubt that the point of this amendment is to neutralize a key source of electoral votes for Democrats.
Will California enact the Maine Method? As I noted, in the abstract it seems like a very reasonable idea. The question is whether voters will be able to look past the abstract and recognize the partisan purpose of the proposition. Perhaps some will say that it's the right thing to do on behalf of California, even if other states don't do the same. Regardless, if it passes, it will have major repercussions for presidential elections for years to come.