WASHINGTON — If Donald Trump prefers combatants who aren’t captured, as he once mocked John McCain, he apparently doesn’t believe in taking prisoners, either.

The exception to the rule is obviously truth. But then, veracity is no hindrance to the conspiracy-minded.

Now, Trump points out he didn’t say this “because I don’t think it’s fair,” but lots of other people are saying that the Clintons had something to do with Vince Foster’s 1993 death, which was ruled a suicide.

Lots of people have also said that Barack Obama was born in Kenya. And who led that long march toward Looney Town? None other than Trump.

Reality check: If Obama were born in Kenya, and if the Clintons could so handily orchestrate a murder with impunity, then couldn’t they have been able to pull off something as simple as a rigged birth certificate? Eh?

Trump is just clever enough to deflect responsibility for these long-ago, defanged conspiracy theories by shifting blame to others. He’s done the same in rallies. If someone in the crowd shouts an untoward remark about a political opponent, Trump looks amazed and says something like:

Did you hear what he just said? I would never say that Ted Cruz eats puppies for breakfast because I don’t know that for a fact, but this guy just did.

The template has served him well. Fans go wild and Trump has cover. But importantly, the sentiment has been released into the atmosphere and absorbed into the limbic systems of the masses.

Now that Trump has cracked the lid on Foster’s coffin, Clinton-haters can luxuriate in gossip, insinuation and lies while entertaining the fantasy that they’re only interested in “the truth.” And who shall be the arbiter of that truth?

Usually, we rely upon objective third parties, the media or the courts. And though few people are naive enough to believe that investigators, judges and reporters can’t be corrupted, the reality is that Foster died by his own hand. This was the conclusion of the United States Park Police, the Justice Department, the FBI, Congress, special counsel Robert Fiske and independent counsel Kenneth Starr.

Now, really.

If Trump were so concerned about the Clintons’ alleged role in Foster’s death, why, then, did Trump continue contributing to Clinton campaigns and causes? And why did he invite them to his third wedding? Would it be because he consorts with murderers and thieves? I would never say such a thing because that would be unfair, but I hear a lot of people saying this. A lot.

The Clintons surely have an imperfect record, and gallons of ink have been spilled on the graves of their past histories. Some people will believe what they want to believe, facts to the contrary.

But who ever would have believed that Starr, he of the 1998 examination of Bill Clinton’s sex life, would find common cause with his former target? For those too young to remember, Starr’s work revealed every lurid detail of Clinton’s relationship with Monica Lewinsky and ultimately led to impeachment proceedings.

Speaking recently on a panel, Starr said it was unfortunate that Clinton’s legacy is viewed only through the lens of that “unpleasantness.”

“There are certain tragic dimensions which we all lament. That having been said, the idea of this redemptive process afterwards, we have certainly seen that powerfully” in Clinton’s post-presidency life.

Starr has perhaps softened with time. Or maybe his distance from Washington — both as dean of Pepperdine University School of Law and, more recently, as president of Baylor University — allowed him space to reflect on those years.

Then again, maybe the former investigator’s own recent experience as a target has opened his heart. On Tuesday, news leaked that Baylor’s Board of Regents reportedly voted to fire Starr amid a sexual-assault scandal involving the school’s football team.

The nastiness of politics knows no physical boundaries, and campus punishments, we’ve observed, don’t always fit the crime.

One thing we can be reasonably sure of is that had Starr discovered evidence that the Clintons were involved in Foster’s death, he wouldn’t have hesitated to present his case. That he didn’t should put to rest any continuing nonsense to the contrary. The case is closed.

Would that this election were, too, but the long, hot summer awaits. For refreshment, we can entertain the prospect of Baptist bros Clinton and Starr dipping their toes in Nantucket’s chill waters, sipping wine and bemoaning the sad state of political affairs. The coarseness, the anger and, might we add, the irony of it all.

Kathleen Parker is a columnist with the Washington Post Writers Group.