Brent Schrotenboer

USA TODAY Sports

SAN DIEGO — The San Diego Chargers are back on the attack – and it has nothing to do with their preseason game Friday night against Arizona.

The team instead has come out swinging against a local political opponent, City Councilman Chris Cate, who says the team’s proposal to build a new stadium is a bad deal for taxpayers.

The team’s campaign committee recently has circulated paid advertisements on Facebook that sic the dogs on him.

“Why does Chris Cate want the Chargers to leave San Diego?” the ad says. “Please call and ask him.”

It then publishes his office phone number.

Some Chargers fans responded by sharing the ad or responding to it with comments.

““He’s an idiot,” one of them wrote on Facebook.

“(Expletive) Chris Cate,” wrote another.

The ad is part of curious campaign strategy by the team as it tries to convince local voters to approve a new taxpayer-funded $1.8 billion stadium and convention center. If the November ballot initiative fails, the team might leave San Diego for Los Angeles, where it has an optional deal to share a lucrative new stadium with the Los Angeles Rams.

Cate told USA TODAY Sports Thursday the Chargers campaign even has made a telemarketing push this week in which those who answer the phone are told that Cate “wants the Chargers to leave San Diego.” The phone campaign then offers to transfer them to Cate's office phone.

He said his office received about 200 calls, including many that were polite, some that were belligerent and one threat that was referred to the police.

“It has gotten personal,” said Cate, a Republican. “I think having fans call my office will have zero impact on how the measure performs on Election Day. I’m surprised to see this level of investment and how they're really trying to attack me, as opposed to promoting their position or answering any questions that I’ve raised.”

Cate said he wouldn’t be bullied into changing his view of the proposal. He also has limited influence on the issue because it’s a citywide election to be voted on by San Diego residents, not the city council.

So why the focus on a 33-year-old councilman who was elected less than two years ago?

The Chargers campaign didn’t immediately return a message seeking comment. But there are theories.

Brian Adams, a political science professor at San Diego State, says the strategy is “fascinating” and a warning shot to other politicians in San Diego.

Polls have shown that public subsidies for a stadium measure are unpopular, and some political leaders in San Diego haven’t taken a public side on the measure yet, including Mayor Kevin Faulconer, Cate’s former boss. If more influential politicians fall in line with Cate, the measure could be doomed.

“I think what the Chargers are trying to do here is that they are trying to say to politicians that there is a political cost to opposing their initiative,” Adams said. “They’re saying to other politicians, `If you criticize our initiative and campaign against it, we’re not going to let you off the hook that easy.’ I think they’re using Chris Cate as an example. He’s a good example to use because he’s not politically powerful… You don’t want to be tarred as the politician who lost the Chargers.”

Targeting an enemy in this way also might help boost voter engagement, especially with NFL fans who love to hate their team’s opponent.

Chargers to San Diego voters: Make rival fans pay for new stadium

Ballot Measure C will ask San Diego voters whether they should increase the local hotel room tax from 12.5% to 16.5% to help fund $1.15 billion in bonds for the proposed new downtown stadium and convention center. The Chargers and NFL would contribute the other $650 million of the estimated $1.8 billion cost.

“I’m a Chargers fan,” Cate said. “I want them to stay. I do not want them to leave, but at the end of the day, I just think this just a bad deal for the city and San Diegans.”

The team has contributed more than $3 million so far to the campaign, according to campaign filings. It also has enlisted a number of consultants to help push the initiative, led by David Carney, a strategist who has worked with former Republican presidential candidates Rick Perry and Newt Gingrich.

Under California law, the proposed tax hike requires two-thirds of voters to approve it. It’s a tall order for the Chargers’ campaign, with much at stake.

The Chargers have played in San Diego since 1961, but if the vote fails, team owner Dean Spanos would have until Jan. 15 to decide whether to join the Rams in Los Angeles.

Spanos has no apparent Plan B in San Diego except to play indefinitely at Qualcomm Stadium, which opened in 1967 and is one of the worst stadiums in the league.

If Spanos declines the option to join the Rams, the Oakland Raiders then would have the option to join the Rams in Los Angeles. Like the Chargers, the Raiders are seeking a new stadium, but have no viable long-term plan in Oakland. They have been pursuing a possible stadium proposal in Las Vegas.

Follow sports reporter Brent Schrotenboer on Twitter @Schrotenboer. E-mail: bschrotenb@usatoday.com