On Monday, I called David Axelrod, chief strategist of Barack Obama's 2008 presidential campaign, with a simple question: How would he advise a Democrat to run against Donald Trump? I assumed it was a topic Axelrod had daydreamed about often in recent months. I was wrong.

"I am just now getting my arms around the reality that I need to think about this," he replied, sounding a bit astonished.

Axelrod's surprise is itself a bit surprising, because Trump perfectly fits a theory that Axelrod has long nurtured about American politics. Presidents, he believes, tend to be followed by their opposites. The careful, aloof, patrician George H.W. Bush was succeeded by the charismatic, brilliant, relatable Bill Clinton; Bill Clinton's successful but seedy presidency gave rise to the disciplined, religious, and decidedly non-bookish George W. Bush; W's blunt, divisive nationalism led to Barack Obama's hopeful, cerebral cosmopolitanism.

And Trump? "He is the antithesis to Obama in the race," Axelrod says.

Axelrod's first rule, then, is to "take him seriously. Don’t look at him through the lens of the elites. Recognize that he’s a salesman, and a very good one. He’ll say whatever it takes to get you in that car."

To attack Trump effectively, Axelrod argues, you need to understand his appeal. "There are a lot of folks out there who want to deal the system a punch in the face, and Donald Trump is the clenched fist."

The mistake Axelrod seems worried Democrats will make is that they'll attack Trump as if he's a normal candidate as opposed to an orange symbol of voter rage. "Because his candidacy is so much about him and his persona, I’m not of the mind that taking him apart on policy will be successful," Axelrod says. "I think you take him apart on his business record and his offensive statements."

The argument here is that attacking Trump's policies is almost a kind of category error: He doesn't take his policies seriously, and it's not clear voters do, either. Trump's appeal isn't the solutions he promises so much as the problems he identifies and is, uniquely among major American politicians, willing to talk about.

The core of Trumpism is that the things he says signal which side he's on — and the backlash to the things he says signals which side all of his opponents are on. Destroying Trump's appeal, then, requires showing that Trump's allegiances are opportunistic and even false — an argument Axelrod suspects will be backed up by careful combing of Trump's business record.

Trump creates some real problems for Hillary Clinton, Axelrod admits. "She’s thoroughly part of the establishment in an anti-establishment year." It's easy to imagine Trump crisscrossing the country demanding she release transcripts of her Goldman Sachs speeches and mocking her email travails.

But Trump also solves some real problems for Clinton: "There’s been a lot of speculation about Hillary and the lack of enthusiasm she’s generated. There’s been a lot of speculation about a fall-off in Democratic participation in this primary. But Donald Trump will ignite the Democratic base. He and the Supreme Court blockade will be great assets in energizing Democrats."

Everyone agrees that Trump has upended the normal rules of American politics. Over the course of a Republican primary, he has defended Planned Parenthood, praised the Canadian health care system, attacked Fox News, skipped debates, retweeted white supremacists, and bragged about how he paid Bill and Hillary Clinton to come to his wedding. And amidst it all, he's simply risen in the polls.

One interpretation of Trump's campaign, then, is that he's proven the traditional rules of politics are obsolete. Another interpretation is that something very strange is going on inside the Republican Party — but whatever it is, it's not going to hold true in the GOP primary.

"I was with James Carville a few months ago and he said, 'The thing I like best about Obama is he’s driven 40 percent of the Republican Party batshit,'" Axelrod says with a laugh. "There’s something to that. Republicans voters were promised they could thwart Obama, and they couldn’t. But that’s not an issue among Democrats, and it’s less of an issue with independents. So you don’t want to generalize from the Republican electorate to the electorate as a whole."

Hillary Clinton has the perfect retort to "Make American great again"