From left, Miami Dolphins’ Jelani Jenkins, Arian Foster, Michael Thomas, and Kenny Stills, kneel during the singing of the national anthem before their first game in Seattle on Sept. 11. Froward County sheriff’s deputies are threatening to boycott the team’s home opener this Sunday. (AP Photo/Stephen Brashear)

The protests started by NFL quarterback Colin Kaepernick — to kneel during the national anthem to draw attention to unfair treatment of minorities — and spreading to other players and other sports have drawn support from some, anger from some, and a direct response from some police officers: If you don’t respect our flag, we won’t work security for your games. A boycott.

Now there’s an important distinction to note before the discussion starts: Some police officers and sheriff’s deputies work sporting events as an on-duty assignment, and some work as an off-duty job for extra pay. Different teams make different arrangements. [The Redskins use on-duty Prince George’s police officers.] Those who are assigned to work a special event while on duty do not have the option of boycotting it, unless they want the option of being fired for insubordination. But those who choose to take an off-duty job can also choose not to take that job. And in the cases of the San Francisco 49ers and the Miami Dolphins, the threats to boycott have come from off-duty officers.

So: Can a police officer exercise his First Amendment right to free speech by choosing not to work an off-duty security detail?

The issue cooled in San Francisco, where Santa Clara City officers backed off of their proposed boycott of off-duty work for the 49ers at Levis Stadium. But it’s coming to a head this Sunday in Miami, where the Dolphins have their home opener, and the union for Broward County sheriff’s deputies is urging its members not to work off duty to escort the team buses and other vehicles to and from the game on Sunday. [Miami-Dade police officers work on-duty assignments at the newly named Hard Rock Cafe Stadium and are not part of the boycott discussion.] Some Dolphins players have knelt during the national anthem at the first two away games.

“I respectfully ask all members of law enforcement not to work any detail associated with the Miami Dolphins unless ordered to do so,” wrote Jeff Bell, president of the Broward Sheriff’s Office Deputies Association in a letter to his members last week. He said the boycott should last “until such time the Miami Dolphins and the National Football League set forth a policy that will not tolerate the disrespect of the American Flag and National Anthem during any sanctioned games or events.”

I spoke with Bell on Tuesday. “I fully support the Dolphins expressing their beliefs. The only thing we’re saying,” he said, “is there’s a better venue for this than during the national anthem while the TV cameras are on them.” He said the Dolphins often honor the military during pregame ceremonies, “and then two seconds later, 50 feet away, there’s a player taking a knee while we celebrate” military accomplishments.

Bell said that he had received overwhelming support for his boycott call, and that “It is a First Amendment issue. That’s why the union is being the voice. As you’re wearing the uniform, we don’t have any First Amendment rights. Even off duty, we’re held to a high standard. We don’t always get to voice our opinions. I challenge these players to get out here with these police departments and get involved in the community to help us resolve the issues we have.”

Jeffery Robinson, deputy legal director of the American Civil Liberties Union, said he did not have a problem with cops choosing not to work an off-duty detail. That is their right, for whatever reason, Robinson said. But he did not appreciate the critique that a football field on a Sunday wasn’t the proper place for a protest. He said Martin Luther King Jr. noted that he received the same criticism in his “Letter from Birmingham Jail,” that people were advising him the time and place weren’t right for his actions.

“For years now I have heard the word ‘Wait!'” King wrote in 1963. “This ‘Wait’ has almost always meant ‘Never.'”

Robinson asked, “When is the time or the place? If this isn’t it, when is it? Black people are being killed in outrageous numbers, it’s a historic and systemic problem. The people that are so upset and incensed that a professional athlete would choose to kneel during the anthem, what kind of outrage have you shown over the shooting of black people in America? What is really says is don’t interrupt my Sunday afternoon.”

Robinson added of the criticism of Kaepernick and others, “The people who claim to be our protectors are advancing an agenda that is the absolute opposite of everything America is supposed to stand for. And that, in my view, is sad. And it speaks of cowardice.”

Police leaders have not gone so far as to endorse a boycott of the NFL. But they have not muted their outrage.

“I think that what the players are doing is disgusting,” said Terry Cunningham, chief of the Wellesley, Mass., police and president of the International Association of Chiefs of Police. “American soldiers laid down their lives to protect their right to protest, which I understand. But find a respectful way to do it, don’t do it during the national anthem.”

Cunningham noted that for off-duty cops, a boycott is “a personal decision that they need to be able to make, and this one strikes a nerve. But I am confident that the officers out there will ultimately do what’s in the best interest of keeping the public safe, as much as it pains them to do it. They’ll do the right thing.”

The Fraternal Order of Police, the nation’s largest police union, has not taken a formal position on NFL boycotts, though their executive board just met last week. But executive director Jim Pasco noted that anyone turning down an off-duty job is hurting themselves financially, and in many cities they already don’t earn high salaries.  “They’re going to pay for their principles right out of their pocket,” Pasco said.

One group that has taken a stance is the National Organization of Black Law Enforcement Executives, which describes itself as “the conscience of law enforcement by being committed to Justice by Action.” But NOBLE does not support the boycotts, organization president Perry Tarrant, an assistant chief in Seattle, told me Monday.

“It tends to undermine public trust,” Tarrant said, “if you are putting your personal beliefs ahead of your obligation to uphold the Constitution.” He said it didn’t matter if the officer was on- or off-duty. “You’re leveraging your position as a police officer to get the job. NOBLE’s position is there is no differentiation, as a police officer, you can’t turn on or off when it’s OK to defend the Constitution. The job goes well beyond the on-duty/off-duty switch.”

Tarrant added, “Whether it’s the right way or otherwise, the conduct by Colin Kaepernick is a First Amendment right. We are sworn to protect individuals expressing those rights.”

In Miami this Sunday, the Broward County sheriff is not expecting a noticeable boycott, and spokeswoman Veda Coleman-Wright noted that the deputies signed up for this duty long ago. “Once they sign up and it’s approved,” she said, “they’re expected to show up for the detail. I haven’t heard that we weren’t going to have enough people.”

Will the off-duty Broward deputies exercise their right to free speech by not showing up? If they do, they’ll be fanning the controversy, which Cunningham thinks is counterproductive, and hurting themselves financially in the process.