WASHINGTON -- Donald Trump has decided that sexism in the quest for victory is no vice.
Trump's supporters have regularly asked why his long string of primary successes has not led his Republican opponents to accept him as "the presumptive nominee," the phrase he used about himself last Tuesday night.
The candidate helpfully answered the question by showing that there is nothing normal about his campaign for the presidency.
A candidate on the verge of taking it all is usually gracious about his foes inside the party and conscious of the need to broaden his appeal beyond it.
But graciousness is not a Trumpian concept.
On his most glorious night so far, he again showed Republicans why choosing him would produce an avalanche of Democratic votes from American women -- and from many men who respect women more than Trump seems to.
"If Hillary Clinton were a man, I don't think she'd get 5 percent of the vote," Trump said of a woman who happens to have been, among other things, secretary of state and a twice-elected U.S. senator from New York. "The only thing she's got going is the woman's card. And the beautiful thing is, women don't like her."
But nothing is more likely to bring women her way than attacks from a brute, and Clinton made no effort to disguise her eagerness to join the brawl Trump started.
"If fighting for women's health care and paid family leave and equal pay is playing the woman card," she said with a broad smile, "then deal me in!"
Far from backing away on Wednesday from his gender war, Trump escalated it.
"I haven't quite recovered -- it's early in the morning -- from her shouting that message," Trump said on "Morning Joe."
And, yes, Trump said, he knew he was courting charges of sexism. "I know a lot of people would say you can't say that about a woman," he added, "because of course a woman doesn't shout."
It's helpful when your opponent underscores your own talking points.
For good measure, Trump took a pre-emptive shot on "Good Morning America" at Carly Fiorina, even before Ted Cruz announced that she would be his vice presidential running mate.
Trump's criticisms of her, of course, were "not because she's a woman."
Trump is the champion of subliminal messaging.
He loves to remind us that his candidacy depends on the regular mobilization of intolerance.
All this is why -- despite his big wins on Tuesday in Pennsylvania, Maryland, Delaware, Connecticut and Rhode Island, despite his large delegate lead, and despite the manifest weaknesses of his two remaining opponents -- Trump is still no sure thing for the GOP nomination.
This Tuesday's primary showdown in Indiana is crucial. So are the still widespread fears among Republicans that a Trump nomination would lead to a November bloodbath for their party.
For all the talk of hard feelings between Bernie Sanders and Clinton, whose four wins this week effectively sealed her nomination, the Republican Party is more divided ideologically and less sanguine about its front-runner.
An NBC News/Wall Street Journal poll earlier this month found that while 78 percent of Democrats said they could see themselves supporting Clinton, only 61 percent of Republicans said this of Trump.
Trump consistently loses to Clinton in hypothetical matchups because of her 20- to 30-point margins among women. Trump seems determined to make that gap even wider.
And if Sanders' strong showing among young voters defines a Clinton problem for the fall, Trump is the obvious solution.
A poll of 18- to 29-year-olds released on the eve of Tuesday's primaries by Harvard's Institute of Politics showed that among voters under 30, Clinton received 61 percent to 25 percent for Trump.
Trump has exposed the timidity of the GOP's leadership class and the bankruptcy of an old conservative ideology that can no longer rally the faithful.
For their part, Ted Cruz and John Kasich aren't doing a very good job of cooperating even though their survival depends upon it.
But Trump has yet to kick his habit of reinforcing for all but his most loyal supporters how unsuitable he would be as a nominee.
He made another stab Wednesday at looking presidential with an "America first" foreign-policy speech offering bits of specificity that most serious candidates would have put forward months ago.
The fact that Hillary Clinton is beaming is why so many in Trump's party are frowning with apprehension.
There remains one man who can beat the front-runner.
His name is Donald Trump.
E.J. Dionne is a nationally syndicated columnist.