DES MOINES – Just a few hours before the Iowa caucuses opened, Don Acheson, a general contractor from West Des Moines, remained as he had been for months: wracked by indecision.

First, he had been for Rick Perry, then Newt Gingrich. When I caught up with him, he was preparing to give Rick Santorum a hard look, but Mitt Romney was “not far behind” in Acheson’s esteem.

“This late in the game I’ve never been undecided before,” he lamented. … This probably is the most bizarre caucus I’ve been to.”

His drift is typical, and revealing. In a Des Moines Register poll published three days before the vote, fully 49 percent of likely Republican caucus-goers said they had not firmly made up their minds. This is what caused the extraordinary volatility in the polls and a parade of seven different front-runners, culminating in Tuesday’s virtual tie between Santorum and Romney, with Ron Paul just behind them.

Much of the political world has come to regard Iowans as a bit flaky. The prospect that the indecisiveness could allow a gadfly such as Paul to win prompted many commentators to write Iowa obituaries: It could “do irreparable harm” (Politico), “discredit the Iowa caucuses” (Fox’s Chris Wallace) and perhaps bring about “the demise of Iowa” (handicapper Stuart Rothenberg).

I disagree: The Iowa Republicans’ indecision captures perfectly the existential struggle within the GOP nationally and within conservatism. They don’t know what they want — or even who they are. Are they tea partyers? Isolationists? Pro-business? Populists? Moralists? Worried workers? Do they want the corporate caretaker (Romney), the oddball isolationist (Paul) or the cultural warrior (Santorum)?

Tuesday night’s returns indicated that Iowans never did make up their mind, as the three men carved up the vote almost evenly. A poll of voters entering the caucuses found that nearly one in five said they hadn’t chosen a candidate until Tuesday.

In their internal conflicts, Iowans fulfilled their first-in-the-nation status, by faithfully acting out the Republican fissures. “The jumble at the top is very reflective of the Republican Party nationally,” argued David Yepsen, the longtime Register political writer now with Southern Illinois University. “It’s activists here reflecting activists all over the country: Who are we? What are we for?”

“This is a fight for the soul of the party,” former Republican National Committee chairman Michael Steele told me this week.

The final events before the caucuses neatly demonstrated this. Romney, suffering from chronic awkwardness known as Al Gore’s disease, took the stage in jeans and penny loafers, with a phalanx of lawmakers behind him to show support. He spoke as if lecturing (“output per person is the highest in the world”), which induced audience members — even the officeholders onstage — to scan their smartphones.

To affect passion, Romney read a few lines from “America the Beautiful.” To affect jocularity, he said his kids refer to his wife as “The Mitt Stabilizer.” This produced laughter — from members of the press corps, who couldn’t picture Romney requiring extra stability.

Like their candidate, Romney supporters are a pragmatic if uninspired bunch. There were only about 100 of them on hand for the final rally in Des Moines, leaving many seats empty at the event’s start time. Those who applauded their man did so for a grand total of six seconds. The one passionate Romney supporter I found (“I love Mitt!”) was a London School of Economics student who admired Romney’s electability.

The Paul supporters, by contrast, were all heart. Not allowed inside to see the candidate’s final speech (to a group of students), they stood in the cold for hours, waving signs and waiting for a glimpse of their man. They shouted: “We love you, Ron!” And: “Forty-fifth president!” When Santorum left the same event, they heckled him.

“I took the day off work for this,” said insurance salesman Justin Yourison, a Paul precinct captain. “If he doesn’t get the nomination, I’m not voting for anyone else. … If the GOP doesn’t let us in, they can do without us.”

If the Romney supporters were cerebral and the Paul supporters passionate, the Santorum supporters didn’t know quite what they were. At one of Santorum’s final appearances, he buttonholed one undecided voter, Sue Koch, and asked her, repeatedly, to caucus for him. She finally told him she would.

When the candidate walked away, Koch gave a shrug. “I had to say something,” she said. 

Dana Milbank is a columnist for The Washington Post Writers Group. He can be contacted at danamilbank@washpost.com