On Nov. 8, 2016, Americans will choose a new president.

But more than 15 months before that, Fox News will choose which Republican presidential candidates get to participate in the White House race’s first debate.

How? By averaging absurdly early poll results and allowing only those from the top 10 of a crowded field on the stage for the Aug. 6 event at Cleveland’s Quicken Loans Arena.

That’s a shame. There are already 14 announced GOP candidates. Add Scott Walker, scheduled to announce his bid next Monday, and John Kasich, due to enter the fray on July 21, and that will raise the field to 16.

Excluding six candidates from the Aug. 6 debate on the basis of very small (and within the polls’ margins of error) differences in public support in extremely premature surveys is no way to give voters, GOP or otherwise, a fair and balanced look at potential presidents.

As Politico reported Tuesday:

“Every candidate — with the exceptions of Jeb Bush, Scott Walker, and Marco Rubio — is in danger of losing his or her place. That leaves the rest of the field hoping their numbers will tick up at just the right time, knowing that the tiniest fluctuation of numbers could be the difference between acceptance and rejection.”

For instance, Mr. Kasich looks like a long shot for breaking into the top 10. So unless Fox News changes its inclusion policy, that would leave Ohio’s governor out of that presidential debate in his own Buckeye State.

Unlike most presidential candidates in either party, Mr. Kasich has experience as a both a federal legislator (U.S. House, 1983-2001, serving those last six years as Budget Committee chairman) and chief executive of a state.

Lindsey Graham also appears at imminent risk not making the top 10. Yet our state’s senior senator has earned an impressive national reputation for foreign-policy expertise and political courage.

Two other candidates who might be, but shouldn’t be, left on the outside looking in at the initial GOP debate:

Dr. Ben Carson is a renowned neurosurgeon and powerful advocate for free-market conservatism.

Carly Fiorina has big-time business experience as the former CEO of Hewlett-Packard.

If Dr. Carson and Ms. Fiorina miss the opening-debate cut, Fox News viewers would miss their fresh perspectives, which challenge the stale approaches taken by too many career politicians.

Yes, another “non-politician politician,” billionaire braggart Donald Trump, is near the top of Republican polls, albeit in the 10 to 14 percent range, despite his history of rash, offensive comments — including a recent ugly rant about Mexicans.

But at this 2015 stage of the 2016 campaign, name recognition is a huge polling advantage. That gives an ample edge to “The Donald,” who for decades constantly sought — and received — public attention.

Meanwhile, even at “only” 10 candidates, the planned format for the Aug. 6 debate would inevitably confine them to short sound-bite bursts.

So why not divide the 16-candidate field into two eight-person debates — or better yet, four four-person debates?

And why not give the electorate more, not fewer, opportunities to fully assess all of the presidential candidates from both major parties?