Will Kaback, Julia Shepard and Sam Gittleman knocked on doors in Des Moines on Jan. 30 as part of the Bernie Sanders get-out-the-vote effort. (Ruth Marcus/The Washington Post)

Curt Johansen, 56, is leaning toward Bernie Sanders, but that inclination is irrelevant. Johansen works evenings dispatching mechanics to help truckers suffering breakdowns, which means he can’t vote in Monday’s caucuses, attendance required, with doors closed at 7 p.m. sharp.

Dustin Jividen, a 32-year-old printer, is all-in for Sanders, as is his wife. Will they caucus? Probably not. His wife works evenings, and Jividen would need to find a baby-sitter for the kids, ages 3 and 8. “I don’t think they would really appreciate standing around for a couple hours,” debating the relative merits of Sanders and Hillary Clinton, Jividen said.

Pat Kerr, 64, a receptionist at H&R Block, supports Clinton. She won’t be caucusing either. “I hurt my back,” she said. “I can’t hardly even walk.”

Mary Bradish, 55 and leaning to Sanders, is one of the luckier ones. Her next chemotherapy appointment isn’t scheduled until Wednesday; if it had been a few days earlier, her compromised immune system wouldn’t allow her to be around so many people. “I totally lucked out,” said Bradish, who works at Wells Fargo.

Welcome to my quadrennial rant against the caucus system. The theory is Norman Rockwell heartwarming: neighbors gathered in a communal enterprise of representative democracy. The reality is jarring, as illustrated by conversations with voters I encountered during a canvassing session with Sanders volunteers Saturday afternoon.

The unforgiving demands of the caucus system serve to intensify the voice of the parties’ most committed, and therefore likely most extreme, voters, as others are deterred by the seemingly arcane and time-consuming process. Meanwhile, caucuses disenfranchise nurses, firefighters and others working the night shift, although both parties took steps this year to offer some opportunity for members of the armed forces to participate.

Not surprisingly, the system produces anemic turnout. In 2008, with open contests in both parties, 347,000 Iowans voted in caucuses, compared with 526,000 primary voters in New Hampshire, with less than half the population.

This comparison isn’t perfect — independents can vote in the New Hampshire primary; Iowa caucus-goers must register for a party, although they can do so on-site. But the fundamental point remains: In contrast to the welcome trend of easing participation, for example by expanding early voting, the caucus system makes it harder.

In addition to rekindling my hostility to caucuses, my experience trudging along with the Sanders volunteers offered a sobering ground-level view of campaign operations in an era of supposedly sophisticated, data-driven politics. The Sanders volunteers were high school seniors from Minneapolis; they had taken the bus that morning, along with 51 of their Blake School classmates volunteering on various campaigns (16 for Clinton, the rest for Republicans, primarily Marco Rubio.)

My crew, Sam Gittleman, Julia Shepard and Will Kaback, were given a sheaf of papers identifying target households, a set of Sanders campaign materials and scant instructions about what to say. The voters they would be contacting, Simon Bracey-Lane, a volunteer field organizer from Britain, told them, would likely be Sanders supporters or leaning toward him.

It didn’t quite turn out that way, underscoring that targeting is an inherently messy operation, especially in a caucus state, and reaffirming the degree to which individual voter identification and persuasion is a gritty, game-of-inches operation.

In three hours and 20 minutes, the students knocked on the doors of 42 homes in a working-class section of this city, leaving reminder cards with the time and location of the caucus at 20 homes where no one answered the door.

Of the others, 11 said they wouldn’t be voting, either because of disinterest or difficulty. Four said they backed Sanders, three leaned in his direction, three were inclined toward Clinton and three were undecided or wouldn’t say. One door-knock produced a Republican voter. (The numbers don’t total exactly because some locations included more than one voter.)

Two others, who said they didn’t plan to caucus, included one voter who said of Sanders, “That guy makes my blood boil” and another who described himself as “a Second Amendment follower.”

So much for micro-targeting. In one driveway identified on the canvassers’ sheet, a man was working on his car. “Not interested in it,” he told them. “Don’t even know what the hell it is.” Which is a rather impressive feat of ignorance in an environment drenched with campaign advertising and non-stop robocalls, not to mention chastening for those who think every Iowan, if not every American, is consumed with Monday night’s outcome.

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