More than one of every three Utah voters — 619,000 of them — are unaffiliated with any political party. They may not receive a by-mail ballot for the quickly approaching Super Tuesday presidential primary on March 3 unless they take some action soon.

Salt Lake County Clerk Sherrie Swensen sent letters to unaffiliated voters this week warning that they will not receive by-mail ballots unless they do one of three things.

If they want to vote by mail in the Republican primary, its party rules require that they register as members of the GOP by Feb. 3. President Donald Trump faces only token opposition from six other lesser-known Republicans in Utah’s primary.

If unaffiliated voters want to vote in the far more competitive Democratic primary, they have two options. They could affiliate as Democrats by Feb. 3. Or, because Democrats allow unaffiliated voters to cast ballots in their primary, such voters may merely request a Democratic ballot by Feb. 25 without formally affiliating.

Swensen enclosed a form in her letters to allow voters to take any step they choose. Justin Lee, state elections director for Lt. Gov. Spencer Cox, said other counties are sending out similar letters.

Lee notes that people who want to check how they are registered — or change it, or even register for the first time — may do so online at vote.utah.gov.

Of course, unaffiliated voters who fail to act by deadlines could still vote in person on March 3 by taking one of the same three steps at voting locations.

“We prefer, however, that they do try to get their ballot by mail,” Swensen said. “There are about 212,000 unaffiliated voters in Salt Lake County. It would be a mess if they all show up to polling locations instead of voting by mail.”

A mess is exactly what occurred with the last presidential primaries in 2016. County clerks did not run that election. Instead, the Republican and Democratic parties chose to run it themselves with volunteers at their normal political caucus meetings.

Some voters waited in lines that stretched multiple city blocks, and many gave up and went home. Some polling locations ran out of ballots. An attempt by the Republican Party to allow some of its voters to cast ballots online did not work properly. Other locations ran out of parking, so the elderly or disabled complained they could not vote.

(Leah Hogsten | Tribune file photo) This photo shows long lines and wait times at the Democratic caucus at Clayton Middle School as both registered party members and unaffiliated voters cast their ballots, March 22, 2016.

It was enough of a disaster that the Legislature mandated that the county clerks run the presidential primaries this year and provided funding for it.

Lawmakers also moved up the Utah presidential primaries — which had occurred as late as June in some recent elections, after nominees were essentially chosen by others — to the early Super Tuesday, when a total of 14 states are voting and likely will eliminate many candidates.

“Our voters are excited about voting on Super Tuesday,” which is early enough that their votes will truly matter, said Utah Democratic Party Chairman Jeff Merchant. He added, “That may still seem like a long way away, but ballots will be mailed out beginning Feb. 11 — so it’s coming fast.”

He said the large Democratic field this year also is creating interest.

“We have a lot of supporters of [former Vice President Joe] Biden here, and we have a lot of Pete Buttigieg supporters, a lot of Bernie [Sanders] supporters and a lot of [Elizabeth] Warren supporters,” Merchant said. “So I think it’s going to drive up turnout.”

Other Democrats on the Utah ballot include former New York City Mayor Michael Bloomberg, New Jersey Sen. Cory Booker, Utahn Nathan Bloxham, Colorado Sen. Michael Bennet, Roque De La Fuente III (son of a similarly named GOP candidate), Hawaii Rep. Tulsi Gabbard, Minnesota Sen. Amy Klobuchar, former Massachusetts Gov. Deval Patrick, billionaire Tom Steyer, author Marianne Williamson, and entrepreneur Andrew Yang.

{Chris Carlson | AP file photo) Democratic presidential candidates former Vice President Joe Biden, left, and Sen. Bernie Sanders, I-Vt., speak during a Democratic presidential primary debate on Dec. 19, 2019, in Los Angeles.

Merchant said the Democratic Party allows unaffiliated voters to participate in its primary with hopes that they will continue to vote Democratic in later elections. (Only 12.9% of Utah voters are registered as Democrats, compared to 36.9% who are unaffiliated and 45.4% who are Republican).

“As we encourage people to vote, they may recognize that the values our party has to offer are things they themselves align with. With that, they may begin to vote for Democrats,” he said.

Utah Republican Party Chairman Derek Brown says his party uses a closed primary because for an election “that binds a political party, it makes sense to require that the people making that decision actually be a member of that political party.”

He expects a large turnout on the Republican side, even though Trump is facing only relatively token opposition.

“This will be the first time we’ve been part of Super Tuesday. Also, you will have mail-in ballots in almost all the counties. We anticipate really high turnout compared to previous years simply because of that dynamic,” he said.

Brown added: “We’re confident, of course, that Republicans will select President Trump to be the nominee over the other six individuals [on the GOP ballot]. Notwithstanding that likely outcome, I think there will still be a really high turnout this year.”

The other Republicans on the ballot in Utah for Super Tuesday are businessman Robert Ardini, perennial candidate Roque De La Fuente II (who ran four years ago as a Democrat, then switched to become an independent), businessman Bob Ely (who ran in 2012 as a Democrat), lawyer Matthew John Matern, former Illinois Rep. Joe Walsh and former Massachusetts Gov. Bill Weld.