There have been many instructional moments over the course of this presidential nominating season, but one that particularly stands out, as we near the end of the process, is the unrepresentative nature of caucuses, particularly on the Democratic side.

Recent Democratic primaries in two states have demonstrated how much the caucus process is out of line with primary elections that have much higher participation rates and tend to draw broader swaths of voters. Bernie Sanders’ supporters have spent much time complaining about “closed” primaries in which only registered Democrats can vote, but they conveniently ignore the fact that many of his victories have come in low-turnout caucuses dominated by “true believers” from the party’s far-left wing.

For example, let’s look at the state of Washington, where the Democratic caucuses on March 26 drew about 230,000 participants, and Mr. Sanders won a smashing victory with about 74 percent of the vote. Because the caucuses are what bind delegates in Washington, he won the lion’s share of the delegates. Yet, when Washington held a separate Democratic primary on Tuesday, May 24, it drew in excess of 650,000 voters, and it was Hillary Clinton who prevailed with approximately 53 percent of the vote.

A similar story unfolded in Nebraska, where Democratic caucuses held on March 5 drew only 33,000 participants and produced a 57 percent majority for Mr. Sanders. Yet, in a separate primary held on May 11, more than 78,000 Nebraskans voted Democratic, and Ms. Clinton won 53 percent of their votes. As in Washington, only the caucuses count for purposes of assigning delegates, and in both cases Mr. Sanders won fair and square and is entitled to the delegates he won under the rules.

But let’s face it: the rules stink. And they’ve stunk for a long time. This divergence between primary and caucus states on the Democratic side is not a new phenomenon. A similar dynamic developed in the 2008 Democratic nominating contest, in which Barack Obama dominated the caucus states against Ms. Clinton but often did not do as well in the primary states. For example, in Texas, which held a primary and caucuses on the same day in 2008, Ms. Clinton won the primary but lost the lower-turnout caucuses.

The key problem with caucuses is that they require a much higher level of time and trouble for their participants. There usually aren’t as many locations (which means more travel for many participants), and they usually occur at fixed times, which narrows the field of participants who may have scheduling conflicts. If your caucus is held from 6 to 9 p.m. at a community center 20 miles away, chances are higher that fewer people will participate than if they could travel to a polling place down the street, cast a vote after a short wait and be on their way. If you don’t have several hours to sit through debates and procedural motions, travel to and from a distant caucus site, and finally vote at the end of the process, you can’t go. This disenfranchises people who work evenings, parents who have to be available to transport their children to evening activities, and caregivers who can’t be away for hours on end. A primary would enable them to vote at any time during a 12- or 13-hour window, and in many states, to vote on an earlier date or by mail if they have time conflicts. Very few caucuses involve a vote-by-mail option; if you don’t have the time to block out several hours at the appointed time slot, you’re out of luck.

There is also the issue, on the Democratic side, of the fact that caucuses are an open process in which participants are required to publicly state their preference, and in many cases face pressure from supporters of other candidates to change their minds. For individuals who believe strongly in a secret ballot, or simply that their voting preferences are nobody else’s business, this too can be a daunting prospect.

The caucus system, conversely, tends to favor people who don’t have the kinds of time conflicts that people with other commitments have. This would be younger people, individuals without children, and people with flexible schedules. Think of students and other young adults, who have overwhelmingly supported Mr. Sanders during the course of the Democratic contest. And yet, in primary and general elections, these are the very people who, statistically speaking, are least likely to vote.

In short, the very nature of caucuses tends to allow the tail to wag the dog. They are unrepresentative and exclusive, and as we have seen in Washington and Nebraska, they can be very much at odds with the desires of the larger pool of voters who cast their ballots in primary elections.

The point of this article is not to re-litigate the Clinton-Sanders contest, which Ms. Clinton is winning by every conceivable measurement except rally sizes. It is merely to shine a light on how extremely skewed caucuses are against large segments of the electorate and to urge that states with caucuses revisit the possibility of going to primaries instead in coming elections. Parties do not win elections by merely scratching the ideological itches of their true believers who would crawl through broken glass to participate; they win by building broad-based coalitions of the types that are not built in low-turnout caucuses. It’s time to ditch the archaic caucus system and go to primaries in every state.

Cliston Brown is a communications executive and political analyst in the San Francisco Bay Area who previously served as director of communications to a longtime Democratic member of the U.S. House of Representatives in Washington, D.C. Follow him on Facebook at facebook.com/ClistonBrownPolitics, or on Twitter (@ClistonBrown), and visit his website at ClistonBrown.com.