Losing sucks. Especially if you are not accustomed to losing and Donald J. Trump has built his whole campaign on being a winner who wins.

Campaign slogan: America doesn’t win anymore. Elect me and you will start winning again. In fact, he promised, you will win so much you will get tired of all the winning.

So it is very hard for Mr. Trump, today, to be right smack in the middle of the longest, darkest slump of his campaign.

It has been more than two weeks now since he last won a contest. That was the Arizona primary last month where he beat Ted Cruz by 18 points and snapped up every single delegate the state had to offer.

It will be more than another week before Mr. Trump has a realistic shot at winning another contest.

The recent loss to Sen. Ted Cruz in Wisconsin particularly stung because the state was ripe for an upset victory that would have silenced Mr. Cruz’s argument for continuing on even though he has no realistic hope of clinching the nomination without extraordinary efforts at the convention this summer.

Wisconsin was a ripe opportunity for Mr. Trump because it was an actual primary where voters simply cast ballots, just like they will do in the general election in November. Because of his appeal to a broader cross-section of voters, Mr. Trump has won most primaries, especially open ones like Wisconsin’s where anybody can vote regardless of party registration.

Mr. Cruz usually struggles in these contests and does much better in the convoluted party caucuses and state conventions that restrict who may participate.

General election candidates who emerge from open primaries almost always do better than candidates who emerge from caucuses and conventions because open primaries are a better barometer of the coming moods and dynamics of a general election.

So the question is: Why didn’t Donald Trump upset Ted Cruz in Wisconsin and put this thing away already?

The obvious main reason is that the establishment GOP have soiled their britches at the Trump juggernaut and dutifully coalesced behind Mr. Cruz. It is really amusing to watch Mr. Cruz work so hard at their behest after he has spent so many years at least appearing to be a thorn in their side. (Does Mr. Cruz really think they will rally to his side once — they hope — he has dispatched The Donald?)

But there is another, bigger and more important reason Donald Trump did not upset Ted Cruz in Wisconsin: Mr. Trump did not play to win. Instead, he played — as he often does — to land hard punches, zing vicious insults and score meaningless points.

This is what makes his presidential campaign so damned entertaining.

But now it is time to win. Now is time to start playing president and appeal to new voters who have serious and understandable concerns about his temperament and grasp of the issues. His speech at AIPAC where he laid out clear — and totally unabashedly correct! — policy positions was a terrific start. He should do many more of those and fewer rambling Trump infomercials.

It is time now for Mr. Trump to hang up his Twitter spurs, holster his six-shooter loaded with insults and set into full gallop for the horizon before the sun sets on him and his campaign.

Charles Hurt can be reached at charleshurt@live.com. Follow him on Twitter at @charleshurt.