Having watched the two national party conventions, I will venture to make a controversial prediction:

The future of America looks like the people seated at the Democratic National Convention. America’s past — or at least the gauzy idealization of it that some hold dear — resembles the racial and ethnic makeup of the crowd gathered at the Republican National Convention.

Forget the pundits, the surrogates and the spin doctors blathering about which party’s message will hit home with voters.

From the perspective of millions of Americans who watched the conventions on television, the difference between the parties was striking. At the Democratic convention, the higher range of diversity was genuine, not scripted. No one was strategically placing a few people of darker hues within range of the camera, or drafting them to stand on stage and give a hearty handshake to a candidate.

African-American, Hispanic and Asian viewers could see ample reflections of themselves in the DNC audience. The reaction was visceral, the sort of emotional pull that often drives votes.

A longtime source for stories took to Facebook to post her feelings, which others echoed: “When I looked at the GOP crowd, I didn’t see any diversity. Just one type of person. When I look at Democratic Convention, I saw myself in so many faces. This is the party of the future.”

This is a numbers reality. Demographics don’t lie.

By 2050, the United States will have a minority-majority population. That is well within the lifetime of many of today’s voters.

Two demographic trends are at play: The majority white population, many of them baby boomers, is aging. And growing racial minorities are statistically more likely to be younger, and therefore still in their childbearing years.

Last year, the U.S. hit a historic marker. Births to Hispanics, African-Americans, Asians and other minorities edged ahead of those to non-Hispanic whites. Births among minorities were actually down by nearly 6 percent from the previous year, according to census data. But that factor was offset by the even larger drop in births, more than 10 percent, among non-Hispanic white people.

That means heady changes for the nation are coming. It will take decades, but eventually these shifts will affect educational institutions, the workforce and government.

White voters, especially diligently voting seniors, will remain an important force in politics. But they will have to share power and influence.

Whether demographic changes will work to Barack Obama’s advantage this year is a subject of much debate. The numbers of eligible voters in any one racial or ethnic group is one thing. How many show up at the polls is another. Among Hispanics, almost half of those who are eligible don’t vote.

But looking a decade and more into the future, it seems beyond dispute that Republicans will have to start appealing to nonwhite swaths of America if they hope to compete for the presidency. In fact, this could be the last election where it is possible to stick to the old playbook.

Yes, people of every race and ethnicity were present at the GOP convention. However, a Herman Cain here and a Marco Rubio there won’t do the trick. In Charlotte, network cameras couldn’t focus on one face without also capturing three, four, five more people of different hues in close proximity.

This is how America is really shaded and will be increasingly so in the future.

This is about more than visuals at a party convention. It’s about who is at the table within each political party when decisions are made. The people who don’t have a seat find their perspectives and interests left out.

One party appeals to a broad range of Americans in all their diversity, and seeks to draw them in and unify them. The other only makes gestures in that direction, while selling a message of fear to the nervous white majority.

Which party is heading in the same direction as the nation? And which can deliver on its promises of prosperity, opportunity and justice for all?