I’ve worked in a lot of campaigns and been fortunate enough to be on the winning side far more than losing. Every race is unique but from Florida governor’s races to the first elections in the Congo, there has been one constant: You could be 10 points ahead or 20 behind, but there will always be a group of critics who are convinced they could do it better.

So it’s with apologies I offer up suggestions on how the non-Trump campaigns should take on Donald Trump and win. But the reality is that Trump is on a winning streak and if the dynamic continues, Trump will win the Republican nomination. That’s more than just a political disaster for Republicans; it’s a moral failure and a danger to the country. In all likelihood either Hillary Clinton or Bernie Sanders will crush Trump, but strange things happen in politics and life. If nothing else, Clinton is under three separate federal investigations and, well, she’s just an awful candidate. She could lose to anyone….even Donald Trump.

Trump is a threat to the country most obviously because he of his unstable, child-like temperament. As is the case with many trust-fund babies, Trump has been isolated from the real world by his birth and it’s given him the assumption that he can lash out at anyone without repercussions. The Upper East Side of Manhattan is filled with these aging trust fund types, many who view the model population of New York as their own petting zoo. Mostly they are harmless, sad figures who drift through Truman Capote stories.

But Trump has proven to be more insecure and damaged than most. As a presidential candidate, he has refused to learn even the basics of policy and throws up random idiocies on trade and nuclear policy with the coherence of a patient coming out of anesthesia. He knows nothing and exalts in his stupidity.

Yet he is winning. Why? Mostly he is winning because of the false assumptions so many of the 2016 candidates had going into the race. Most of the 2016 candidates looked at Mitt Romney’s run last time and were convinced they could do much better. They are learning two lessons: First, Mitt Romney was a smarter, tougher, better candidate than anyone else in this race—Marco Rubio and Ted Cruz could both take a note from him on how to stand up to Trump. The second is that the difference between running for president and running for any other office is the difference between junior high sports and the pros.

Governor Walker of Wisconsin, a constant Romney critic, didn’t make it through the few first few debates. Jeb Bush and his inner circle were convinced if only Republicans had a chance to vote for a Spanish-speaking, “joyful” candidate, it would all work out. Cruz thought it was just about being the “true” conservative. And Rubio believed he embodied the future of the Republican Party and the future was now.

No. Campaigns are about conflict. It is absolutely necessary not only to show why you are better but the other candidate is worse. Say what you will about Donald Trump, but he understands that to win a fight, you have to fight. Now the race is at a stage where it is clear to beat Trump, a candidate must engage Trump and drive him from the race. Why isn’t this obvious? It’s what Trump is doing to others and it’s working.

The good news should be that Trump is one of the easiest candidates to engage and defeat in modern history. But no one is taking advantage of his vulnerabilities. To defeat a candidate, you must go at the rationale of their candidacy: Don’t shoot down the airplanes, blow up the aircraft carrier. Romney attacked Perry on his strength: jobs. That’s what it takes. A campaign that beats Trump will have to prove that the core of his message and the messenger both are fakes. Here’s how.

Trump asserts he is a business success and “built a great company.” Don’t let him get away with this assertion and define himself.

Trump has a long history of failures in business. If he had taken his inheritance and put it in an index stock fund, he would be far richer. Taxpayers have bailed out his failures time and again. And as long as he refuses to release a tax return, odds are that he is hiding some dark financial secret. Challenge him on his success. The facts are on your side and it will drive him crazy.

Trump sells himself as a truth teller. Challenge it. In this campaign he has been caught in one slippery contradiction after another, even denying what he had just said hours earlier. Being loud and bombastic doesn’t make him less shifty and dishonest. Hold him accountable. “Just for once tonight, Donald, at least try to tell the truth.” Or “Tonight I want you to watch Donald Trump’s face as he is confronted with one unpleasant truth after another. As he gets redder and redder, you’ll know he knows we are on to his game. Clowns are red-faced and there is no bigger clown to ever run for president than the political con artist Donald Trump. Look, you can see it’s already working. He’s getting redder.”

Trump will help America win? No. Trump’s jumble of policies will take every bad situation and make it worse. His positions on trade are to the left of Sanders and would result in a tax on every consumer in America. That’s a Trump Tax that voters will have to pay. Tell voters about the Trump Tax.

Trump sells himself as someone who will restore America’s pride. No. Putting a guy in the Oval Office who talks about women as a “great piece of ass,” who mocks the disabled, who has boasted over and over again of sexual conquests is a disgrace. In 2000, George W. Bush talked about “restoring honor and dignity to the White House.” Donald Trump makes Bill Clinton look like a minor league wannabe in the competitive sport of hunting women with power and money. Do we really want an Oval Office with Donald “great piece of ass” Trump in it?

It’s a myth that Donald Trump is a candidate with some special powers that make him invulnerable. He’s an undisciplined candidate who is intellectually lazy and emotionally vulnerable. Use those qualities to beat him. Or let him continue to win. That’s the simple choice.