The Millennial picture wasn't looking very good for the Republican party as we know it. They're much less socially conservative than their older counterparts, and more inclined to support folks like Bernie Sanders and Gary Johnson than guys like Donald Trump or Ted Cruz.
But people can change: the Baby Boomers used to be represented by pinkos and hippies. Then look what happened.
But demographic change has a much more sturdy kind of impact, and it's gonna be yuge.
General Outlines Looking Forward
Let's look at race, which seems to be one of the more decisive patterns in voting of late: whites often vote Republican, nonwhites often vote Democratic.
In 30 years time, it's likely that whites will fall to about 50% of the population, from about 82% in 1965. It's a massive change: The US will simply no longer have a majority population.
Immigration may continue to come in fast, as we've seen since 1965, bringing in a whole new host of people with different backgrounds and ideas. From our current 14%, immigrants (that is, people born overseas) are likely to make up over 16% of the population in 30 years.
Hispanics will make up a huge portion of that immigration wave, but as time goes on, Asians will make up an increasingly large share.
The role of religion is likely to shrink in US politics, as well. In just 7 years--2007 to 2014--the number of people whose religion was "unaffiliated" jumped from 16% to 23%--so a percentage point per year.
This is an ongoing generational shift: as populations get younger, they grow less religious--particularly less Protestant (the exception here is the black Protestant population, which has been very stable). Among younger Millennials, there are more unaffiliated than Protestant.
So big picture: we're looking at a future that is much more ethnically diverse, more full of immigrant populations, and less religious--particularly Protestant--than ever before.
Looking at the Maps
Real quick: how would this affect the electoral college? Here are maps of the US's population changing over the next 15 years in different counties, by the Washington Post. More blue indicates more growth; more yellow/red indicates more decline.
In this first map, we see total population changes. So very briefly: we can see that the Southeast and Southwest will see substantial growth; big cities west of the Mississippi will grow, as well. The Rust Belt, Northeast, Breadbasket, and much of Big Sky Country will grow at a comparatively slower rate or shrink.
The implications for the electoral map long-term are straightforward: states like Virginia, North Carolina, Florida, Georgia, Nevada, Utah, Arizona, and Alaska are likely to gain some in their relative electoral vote share. Most of these are conventionally Red states, which might lead one to think that the Republicans stand to gain. But let's cut deeper into the demographics.
The map below shows the growth of the white population in the US. With the exception of Utah, Virginia, and perhaps Iowa, the growth of white voters in these states is fairly modest. In many states, like the Northeast, California, Breadbasket, and much of Texas, the white population may shrink.
To compare, this map shows likely population growth of blacks in America. We see substantial growth in many predominantly Blue states like Vermont and Maine, Wisconsin, Minnesota, Colorado, Hawaii, Oregon, and Washington. But we also see growth of the black population in Utah, Arizona, Iowa, Missouri, Florida, Pennsylvania, and New Hampshire. A number of these are swing states and facing declines in white populations overall.
Finally, if we look at the growth of Hispanics, we see it significantly and almost across-the-board. (Interesting note: there's much less growth in places like New Mexico and Western Texas compared to most of the rest of the country).
This means the map may begin to change. Swing states like Ohio, Florida, Iowa, Pennsylvania, and New Hampshire will become less white and more Hispanic, and sometimes more black. If the Republicans stay on-course, they are likely to face a very difficult electoral map going forward.
These regions with large growth in Hispanic populations will likely see a substantial growth in the portion of the population that identifies as Catholic, rather than Protestant. Catholics tend to be a bit more moderate on social issues than Protestants.
But the Republican Party Will Change... or Die
This is not to say I'm predicting an especially long string of Democratic victories.
What tends to happen in the US--and other two-party systems--is this: one party becomes highly dominant, and in time it begins to fracture, and the other party finds ways to win over a chunk of its voters. This happens for a few reasons:
1) People actually fall into far more than two camps
2) Very large coalitions are unwieldy, as they are trying to balance the conflicting desires of many groups
3) Smaller parties will look for ways to pick off other groups when they're down-and-out
This is generally how parties in the past have either died (Whigs, Federalists, etc) or transformed (the Democrats and Republicans after the Dixiecrat disaster for the Dems). And these forces will repeat in the US again.
But looking optimistically: 43% of Millennials are nonwhite, and a bigger portion are immigrants than any generation alive. Groups are mixing more and meeting each other more. People are getting to know one another.
So maybe--just maybe--the parties of the future will be less about one's demographic group.
But either way: times are changing.