Trump triumphs. Clinton struggles. Who would have predicted that? Soon it will be Donald Trump, who is now the presumptive Republican nominee, versus former Secretary of State Hillary Clinton. Clinton by a landslide in the general election? The great philosopher Yogi Berra once said: “Never make predictions. Especially about the future.” Safer to talk about the past. So what explains Trump’s astonishing political success? The best explanation was given in October by, of all people, the legendary rock star Alice Cooper, who said, “I know Donald, and I know he’s a ‘doer.’ He’s not a ‘sayer.’” That’s it exactly. Trump is a “doer.” Why are so many voters going for that? Because they are exasperated by President Barack Obama. They see Obama as a sayer and a thinker but not much of a doer. Actually, Obama has gotten a lot of things done: healthcare reform, elimination of Osama bin Laden, economic recovery when the country was teetering on the edge of another Great Depression, Wall Street reform, rescue of the U.S. auto industry. Nonetheless, his critics see Obama as ineffectual. They look at Washington, and they see gridlock. They expect a president to get things done. They don’t want to hear, “Congress won’t give me what I want.” Tough leaders like Presidents Lyndon B. Johnson and Ronald Reagan could get what they wanted out of Congress by twisting arms and turning on the charm. Instead, all critics see is that Obama can’t stop Islamic State. He can’t do anything about Russian President Vladimir Putin’s aggression in Ukraine and Syria. They don’t believe he can stop Iran from getting nuclear weapons. He can’t bring well-paying jobs back. As for healthcare reform, most Americans never supported it, and increasing numbers are turning against it. Even Democrats are frustrated, which helps explain their continuing support of Senator Bernie Sanders, (I-Vt.). Obama can’t shut down Guantanamo Bay, Cuba. He can’t deliver immigration reform or gun control. He can’t do much about climate change. Why does Trump come across as a doer? For one thing, he’s a real-estate developer. Last month, Faroll Hamer, a retired planning official, wrote a “Washington Post” op-ed contending that Trump fits the stereotype of a developer — bold, pragmatic, decisive and “megalomaniacal.” In Hamer’s experience, developers haggle and push and scheme and contrive to get what they want. They have no ideology, except success. Trump wrote the book on getting what you want: “The Art of the Deal.” With a builder, the results are there for everyone to see. And benefit from: “Everything they do is for us,” Hamer wrote, “because they are building places for us to live, shop or work.” Builders see themselves as public heroes. In some works of fiction, they are: Ayn Rand’s novel, The Fountainhead,” Henryk Ibsen’s play The Master Builder.” Hamer’s prediction: “Trump really would build a wall.” Trump was surprisingly magnanimous in his comments Tuesday night after the Indiana primary. After Senator Ted Cruz of Texas dropped out of the race, Trump called him an “incredible competitor.” That’s the way developers operate. Once they get what they want, they’re all sweetness and light. There’s another reason Trump comes across as a doer. He’s not a politician. On Monday, Cruz was confronted by pro-Trump protesters as he campaigned in Indiana. An angry young man pointed to Cruz and said, “You are the problem, you politician. You are the problem.” People expect government to solve problems. They’re angry because the federal government can’t solve problems any more. It can’t stop illegal immigration. It can’t keep jobs in the United States. It can’t stop terrorists from killing Americans. Trump says he can do all those things. Most Americans see politics as the enemy of problem solving. Why can’t government deal with the national debt? Because of politics. Why can’t we deal with climate change? Too much politics. Why can’t we control our borders? Politics gets in the way. “For years,” former President Bill Clinton once argued, “politicians have treated our most vexing problems like crime, welfare and the budget deficit as issues to be exploited, not problems to be solved.” Trump offers himself as a strongman. He’ll ignore politics and just get the job done. It’s not quite clear how. But his supporters don’t care. He’ll just do it. It’s the reason why voters have always been attracted to political outsiders like Ross Perot and Colin Powell — and now Trump. They can put politics aside and just fix what’s wrong. Can Trump actually get elected president? It’s not likely. He’s too risky. And viewed as dangerous. Obama warned this week, “He is not somebody who, even within the Republican Party, can be considered as equipped to deal with the problems of this office.” But it’s not impossible. What it would take would be an extraordinary event. Suppose there is another serious financial crash in October. Or, God forbid, a terrorist attack in the United States like the ones in Paris or Brussels. A catastrophe could cause voters to lose their inhibitions. They would be desperate for change. People would start saying, “We can’t go on like this.” That could doom Clinton, who represents the status quo to most voters (“a third term for Obama”). Both parties are experiencing a wave of dissatisfaction with the status quo. It’s putting Trump over the top on the Republican side and fueling the Sanders surge among Democrats. The polls show Clinton’s lead over Trump is narrowing. She will not be an easy candidate to elect. Clinton has a negative favorability rating, an average of 55 percent unfavorable. What she has going for her is that Trump’s unfavorability rating is even higher — 65 percent. The key unknown is turnout. A lot of people might stay home because they don’t want to vote for either Trump or Clinton. But if polls begin to show Trump winning, that could generate a huge turnout of fearful anti-Trump voters. Hamer, the former planning official, warned that developers get into trouble when they “act for short-term tactical gain without principles and without knowing where [they’re] going.” Replacing a thinker with a doer would be a grave risk. Americans could end up with a president who “does” without thinking. The United States has a safeguard against a megalomaniac: the constitutional system. The last time Americans elected a president who had no political experience was General Dwight D. Eisenhower in 1952. His predecessor, President Harry S. Truman, famously predicted: “Poor Ike! He’ll say, ‘Do this!’ and ‘Do that!’ and nothing will happen. It won’t be a bit like the army. He’ll find it very frustrating.” So would “Poor Donald.” Bill Schneider is a visiting professor in the Communication Studies Department at the University of California – Los Angeles