Republican presidential nominee Donald Trump at a rally Aug. 9 in Wilmington, N.C. (Sara D. Davis/Getty Images)

“HILLARY WANTS to abolish, essentially abolish, the Second Amendment,” Donald Trump said Tuesday. “By the way, and if she gets to pick her judges, nothing you can do, folks. Although the Second Amendment people, maybe there is, I don’t know.”

The day after Mr. Trump delivered a relatively restrained speech on economic policy, the candidate once again trampled on Republican hopes that he would suddenly disguise himself as an acceptable politician.

“You aren’t just responsible for what you say,” Gen. Michael Hayden, a former CIA director, said in response to Mr. Trump’s remark. “You’re responsible for what people hear.”

What did people hear? Many no doubt assumed Mr. Trump to be recycling ugly tea party rhetoric that contemplates “Second Amendment remedies,” a term former Nevada GOP Senate candidate Sharron Angle used in her 2010 campaign to suggest armed resistance to government “tyranny.” The voters rightly rejected Ms. Angle at the ballot box, and she receded from public view. But Mr. Trump’s flirtation with such rhetoric poses a greater threat. By seeming to encourage armed insurrection against a Hillary Clinton administration, Mr. Trump has recklessly magnified the danger of his previous claim that the election is being “rigged” against him.

And encouraging armed resistance against the federal government is not the most worrisome of possible meanings. Other listeners assumed that Mr. Trump was encouraging supporters to train their weapons on Ms. Clinton herself.

Speaking at a rally in Wilmington, N.C., Republican presidential nominee Donald Trump said that foe Hillary Clinton wants to "essentially" abolish the Second Amendment. Trump slammed Clinton's ability to pick Supreme Court justices if she wins, saying, "nothing you can do, folks." (The Washington Post)

As is often the case, Mr. Trump was incoherent enough to permit more than one plausible interpretation of his words. If he had not so often celebrated violence and wielded dark innuendo against political opponents, minority groups, journalists and others, it would be easier to give him the benefit of the doubt in this case.

Unfortunately, a spokesman’s after-the-fact explanation did not clear the bar of plausibility. “Donald Trump was obviously talking about American voters who are passionate about their Second Amendment rights and advocating they use that power at the ballot box,” the spokesman said. No; Mr. Trump was talking about what would happen if Ms. Clinton were elected.

If Mr. Trump were not a major-party presidential nominee, his comment Tuesday might have earned him a stern visit from the Secret Service. Instead, it will simply be added to the ever-growing list of Mr. Trump’s disqualifiers — and to the ever-growing burden of Republican leaders who continue to insist that their candidate is suitable to serve.