The electoral college favours white voters

As states have different demographic mixes the electoral college can exaggerate the clout of some voter groups. For example, white people are expected to comprise roughly 73% of an average state’s voters come November. But if the average is weighted instead by how likely a voter in each state is to decide the outcome of the election, the white share of voting power climbs to 79%. That is because the most competitive states are whiter than the national average. 

California, for example. There we estimated a probability of over 50 percent that the state's 55 electoral votes would be required for a win. But there was a probability of less than 1 in 10 billion that the vote in the state would be tied, under this scenario.

In contrast, a single voter's probability of determining the election was highest in New Hampshire, where we estimated there was only a 4 percent chance that this state's electoral votes would be a necessary part of a winning coalition. However, in that circumstance there was a 1 in 40,000 chance of your vote being decisive (if the state's electoral votes were to make the key difference). Multiply these together and you get a one in a million chance of a New Hampshirite’s vote being decisive. Hispanic voters, on the other hand, have a few states solidly in the influential top-right quadrant: Florida, Arizona, Nevada, and New Mexico. But such a high proportion of Hispanic registered voters live in California and Texas — two states very unlikely to decide the election — that Hispanic voters end up substantially less powerful than average.

The current system has a distinct, adverse impact on black voters, diluting their political power. Because the concentration of black people is highest in the South, their preferred presidential candidate is virtually assured to lose their home states’ electoral votes. Despite black voting patterns to the contrary, five of the six states whose populations are 25 percent or more black have been reliably red in recent presidential elections. Three of those states have not voted for a Democrat in more than four decades. Under the Electoral College, black votes are submerged. 

Those whose votes count for less are less likely to bother casting a ballot, it seems. Voters from states that were most likely to decide the election in 2016 were ten percentage points more likely to vote. That suggests that replacing the electoral college might lead to increased turnout.