In a potentially significant political trend, almost half of 6- to 21-year-olds in the U.S. are Hispanic, African-American or Asian, according to a study released today by Pew Research.

Why it matters: Rapidly changing American demographics will have a profound impact on elections, government policies, economic opportunity, and more. "How we deal with this racially diverse generation ... will say a lot about how successful we will be as a nation," says Brookings' William Frey, author of "Diversity Explosion."

The political impact of changing U.S. demographics can already be seen in the high turnout of young Americans in the midterm elections, Frey tells Axios — an estimated 31% of people 18 to 29 voted, the highest since 1994.

For Republicans, the threat is that younger generations, tending to care about abortion, gay rights, and immigration, will flock largely to Democrats, Frey said.

The most notable change has been the rise in the share of Hispanics. A quarter of the post-millennial generation is Hispanic, according to Pew, a growth of 7 percentage points since millennials were their age.

The youngest generation is also the most highly educated, with 59% of 18- to 20- year-olds enrolled in college, compared with 53% of millennials when they were the same age.