By Ken Belson

New York Times News Service

SAN DIEGO — A question of unrivaled consequence has descended on this picturesque seaside city: Should the good citizens root for or against the Chargers, the football team that abandoned them a season ago but didn’t go really all that far?

In years past, the team’s surprising success would be cause for widespread celebration. Fans would proudly wear team jerseys and caps, bars would overflow with viewing parties, and the team would dominate water-cooler talk. The Chargers went 12-4 in the regular season, beat the Baltimore Ravens on the road in an AFC wild-card game, and now have a chance to topple the New England Patriots in Foxborough, Massachusetts, on Sunday in the divisional round.

But ambivalence has dominated San Diego’s cool ocean breeze of late. After a long, messy fight over funding for a new stadium in San Diego that was never built, the Chargers left for Los Angeles in 2017, forcing legions of jilted fans to decide whether to follow the team north, or wash their hands of the beloved Bolts.

Last year, the team began with four losses and missed the playoffs by a game, which made it easier for bereft fans to move on. Talk radio hosts trashed the team, an angry fan flew scathing banners over the team’s new home in Carson, about a 45-minute drive south of Los Angeles (without traffic), and one restaurant owner gave out free tacos after every Chargers loss.

Now the Chargers have returned to the postseason for the first time since 2013, recording their most wins in nearly a decade. The calculus has changed.

Some fans are creeping back, making the 100-mile drive to Carson to watch the team or packing team-friendly bars on game days. For other fans, the Chargers’ success has deepened their resentment.

“It’s been a civil war and it’s getting worse because the team is good,” said Johnny Abundez, who is part of the fan group Bolt Pride and has been attacked for his continued allegiance. “The fight for San Diego has gotten personal.”

The rancor reached a fresh peak this week, after the Chargers upset the Ravens. A detractor on Twitter encouraged people to write bad reviews on Yelp of Cali Comfort BBQ, a sports bar whose owner, Shawn Walchef, has stood by the Chargers and hosts popular viewing parties on game days.

“It’s OK to disagree, but not to be disagreeable,” said Walchef, who has four Chargers season tickets at Dignity Health Sports Park, the team’s temporary home.

Fans and former fans in San Diego have been bickering for years over whether to support the Chargers, but the effort to destroy someone’s business crossed a line. A host of people jumped to Walchef’s defense, including one of the team’s most vocal opponents, Victor Lopez, who owns El Pollo Grill, a Mexican restaurant.

Lopez, 42, is the restaurateur who was so angry that the team abandoned his hometown that he began giving out tacos after the team lost. The lines went out the door on Mondays and Tuesdays after defeats. He has given away about 4,000 tacos, by his estimate, but the publicity has brought Lopez an unexpected windfall. While some Chargers faithful stopped coming to his restaurants, many others have flocked.

Lopez said sales were up about 25 percent because of the promotion. “But I’d give it all back to get my team back,” he added.

Still, the attacks on Walchef were too much, and Lopez, who said he once received a death threat, has defended his fellow restaurateur. In the spirit of civility, they made a bet: If the Chargers beat the Patriots on Sunday, Lopez will feed Walchef’s staff. If the Patriots come out on top, Walchef will send barbecue to Lopez’s workers. The loser will also donate to a ­GoFundMe campaign to help a local sports radio show host whose son recently died.

The passions over loyalty to the Chargers in San Diego are a distant battle in Los Angeles, where the team is trying to find a foothold. The team plays in a small soccer stadium where visiting fans are often out in force, raising questions about whether the Chargers will be able to fill the 70,000-seat stadium they will share with the Rams starting in 2020.

The team’s recent success has eased some of those concerns. Sales of seat licenses at the new stadium being built in Inglewood have been brisk immediately after Chargers victories. Television viewership has ticked up in Los Angeles (and San Diego) after the team pulled off dramatic victories in Seattle, Pittsburgh, Kansas City and Baltimore. The Chargers are hopeful the team’s resurgence will help them lock in key sponsors and a naming-rights partner.

“Timing is everything,” Dean Spanos, the team’s owner, said at the Chargers’ practice facility in Costa Mesa this week. “Monday mornings are great when you win the playoffs.”

Still, winning over fans in Los Angeles will take time. The Chargers previously played just one season in Los Angeles, in 1960. The city is filled with transplants who root for their hometown team, and locals adopted other teams during the NFL’s two-decade absence from the market.

The Rams, who arrived from St. Louis in 2016, have also battled the perception they are unloved in their new/old home. The team has a longer history in Los Angeles, having played in the area for nearly 50 years. But Rams home games are on occasion overflowing with fans of the visiting teams at the cavernous Los Angeles Memorial Coliseum.

The Chargers, though, are in an unusual position. While most fans in St. Louis have washed their hands of the Rams, the Chargers’ biggest group of supporters are within driving distance, though many are unwilling to make the trek to Carson.

“I understand how the San Diego fans feel,” Spanos said. “I knew coming up here it was going to take maybe a generation to build that kind of fan base.”