Sen. Bernie Sanders (I-Vt.) at a caucus night rally Monday in Des Moines. (Alex Wong/Getty Images)
Opinion writer

Who will win the Republican and Democratic nominations is still anyone’s guess, but the Iowa caucus voters defined three themes that are likely to roll through the rest of this year’s campaign: alienation, disruption and resilience.

Let me unpack those words. Our political system has been shaken by the anger of middle-class voters who doubt the elite’s political nostrums; the insurgent candidates’ provocative, populist counterarguments have had a disruptive effect on both parties; and yet, the most extreme and demagogic responses seem to have been rejected by a resilient electorate.

How will this fractious campaign look to people overseas who are at once hungry for American leadership and dubious about its staying power? I hope they will see that the United States is in a necessary process of internal renewal and reinvigoration. We’re grappling with the same issue facing all advanced economies — how to revive growth and distribute its fruits more fairly. A United States that can tackle that problem head-on can perhaps help revive a stagnant global economy.

Foreign fears of a U.S. implosion should diminish, too: The likelihood that the bombastic Donald Trump will emerge as the winner — which a week ago provoked gasps, quite literally, from European friends of the United States — now looks a little less likely.

After Iowa, it’s a mistake to pretend that voters aren’t angry with conventional, middle-of-the-road solutions and prepared to listen to unconventional ones. That’s the message of Bernie Sanders’s success in battling Hillary Clinton to a near-draw in the Democratic caucus. And it’s a mistake to think that if only Clinton, or Marco Rubio on the Republican side, could package mainstream politics better, the country would get on board. The next president isn’t going to limp to the finish with a warmed-over, pepped-up version of the past.

The disruptive idea this year, as David Corn of Mother Jones has described it, is that the system isn’t working well enough to maintain the living standards of the vast bulk of Americans who live between the coasts. This doesn’t mean that Sanders has the answers; from what we’ve seen so far, his proposals for free college and universal health care would push the country further toward insolvency and division, rather than prosperity and unity. But he is engaging the issues that concern the country in a straightforward, constructive way.

You can’t call Sanders a crank or an accident anymore. He embodies something real. My favorite Iowa campaign moment came last week when Sanders asked a woman at a rally to describe what it was like to live near the poverty line. She tearfully explained the difficulty of caring for her family, and the shame. Any American who didn’t get a lump in the throat listening to her emotional words has lost touch with what “pursuit of happiness” means.

What other lessons can we take from Iowa? I wish I could write off Trump as the man who “could not close the deal,” as Tom Bevan wrote Tuesday on RealClearPolitics. Or that I could agree with the Daily Beast that, with Ted Cruz’s GOP victory, to quote one of Trump’s own vainglorious tweets, “no one remembers who came in second.”

What we do know is that Trump’s blowhard, professional-wrestling-promoter style failed to capture an Iowa Republican electorate that identified itself as 64 percent “evangelical.” The polls had suggested that these voters would be swayed by Trump’s constant boasting that he was a “winner” and ignore this self-declared evangelical’s comic mistake Sunday of nearly putting money into the plate of Communion wafers. It turned out that Iowans had better sense.

Another obvious post-Iowa lesson is that Clinton is going to have to become a better candidate. And by that, I don’t simply mean that she has to buff her image and give better speeches. No, what Clinton really must do now is engage the economic issues that animate the alienated Sanders, Cruz and Trump voters.

The electorate senses the “secular stagnation” in the economy that Lawrence Summers, a former treasury secretary and longtime Clintonite, has been talking about the past three years. Summers and other economists have been discussing radical ideas to spur growth and foster equality that go beyond the usual establishment trinity of trade, technology and transfer payments. Clinton needs to embrace them.

A disaffected United States can be drawn into a civilized — but disruptive — dialogue about political change and reformation. That’s a positive message from Iowa, at home and abroad.

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