HUD Secretary Julian Castro in May. (Stephen Voss/Stephen Voss )

The writer was U.S. ambassador to Belgium from 2009 to 2013.

Already tired of the 2016 race?

So many candidates, so much noise, but ultimately so little true drama. Prognosticators try to create a tough-to-call race like circus performers who fail twice at some daring stunt in order to build the tension for the third and final attempt.

So let’s turn to a more grown-up question: Who will be president of the United States in 2031?

It’s down to four.

First, the easy part. Hillary Clinton will likely win by about 3 percent — both in 2016 and 2020.

There is some legendary historical wisdom explaining the limits of an incumbent party’s ability to hold the White House for successive terms. But legends often fall to modern reality.

And here is the modern reality. A Texan named George Mitchell taught the United States how to frack its way to abundant energy. Europe decided not to and Japan can’t find anywhere to do it. So the United States developed an energy advantage to go along with a labor advantage and, within a few years, was transformed from an energy-crippled, economically withering country to a vibrant manufacturer and energy exporter. Unemployment is down to 5.3 percent and, with two trade agreements expected in the next two years to further lower export hurdles, our economy will remain robust until the rest of the world can figure out how to get off coal and oil at a reasonable price (thus, for the next decade).

And we have almost no combat boots on the ground anywhere in the world.

With a strong economy supporting the status quo and no wars to challenge it, demographics will decide presidential elections.

As a matter of modern demographics, the Democratic coalition (urbanites, women, blacks, Hispanics, gays, the young and the like) beats the Republican nice-rich-white-guy coalition 51 percent to 47 percent. (See Obama vs. Romney.) And with Jeb Bush seemingly stepping in for Mitt Romney in 2016, another legendary adage comes to mind: “The definition of insanity is doing the same thing over and over again and expecting different results.” Running essentially the same demographic race as in 2012 under stable economic and combat conditions yields essentially the same result. Correcting slightly for Bush’s sincere run at the Hispanic part of the coalition, it’s probably Clinton by 3 percent for the next eight years.

The growing demographic gap, supported by the status quo of an energy-advantaged economy and the change in the nature of warfare (with Sunni countries fighting the extremists of the day instead of U.S. Marines) should last long enough to carry the 2016 and 2020 Clinton veep to the White House from 2025 into 2032.

So the president of United States in 2031 is . . . .

Down to four right now. Two Hispanics — former senator and secretary of the interior Ken Salazar and former mayor of San Antonio and current Secretary of Housing and Urban Development Julian Castro . And two white males with gubernatorial experience from a swing state — former Virginia governors, now Virginia’s U.S. senators Mark Warner and Tim Kaine. (Full disclosure: Both are old law school friends of mine.) Yes, Gov. Jay Nixon of Missouri also qualifies but difficulties relating to the Ferguson tragedy narrowed the field.

The pick will be down to one by July 21, 2016.

If as of that date — the end of the Republican convention — Bush is running better with Hispanics than Romney did in 2012, due either to his family and personal life or because he took a shot at the demographic inequality by adding a Hispanic woman (New Mexico Gov. Susana Martinez) to his ticket, then Clinton will have to bolster her appeal with Hispanics. In that case, welcome 2016 and 2020 vice president and 2024 — and thus 2031 — President Salazar or Castro. Though we are still on the early holes and much will depend on the Bush VP selection, Castro would appear to be higher on the leader board, as he provides youth to the seasoned Clinton and is more closely identified with the Hispanic community.

If Clinton’s advantage with Hispanic voters is holding true to Obama’s numbers, and Bush does not choose a Hispanic for the No. 2 slot, perhaps going instead with one of the 2016 also-rans or Gov. Nikki Haley of South Carolina, then Clinton can ill afford to offer up the first ticket in history without at least one white male. And while focusing on this white male shortfall, Clinton can also address her lack of gubernatorial experience and secure help with a swing state. In that case, raise your right hand, Warner or Kaine — now and through 2032.