BOSTON — They marched under the motto, "It's great to be straight." A man in a shark costume chanted, "Straight lives matter!" Another dressed as Santa Claus held the "straight flag" and welcomed any heckling that came his way.

After months of build-up and debate, drawing the attention of late-night talk shows and the scorn of many in this liberal city, a few hundred marchers took part Saturday afternoon in a Straight Pride Parade in Boston.

It turned into the spectacle that some predicted – chaotic and contentious – and a reminder of the nation's deeply divided politics.

The conservative-aligned marchers – many wearing "Make America Great Again" hats and other gear promoting President Donald Trump – started from Copley Square with a "Trump bridge" serving as the primary float. They held American and Israeli flags while Lee Greenwood's "God Bless the U.S.A." blasted from speakers. A man dressed as a giant dinosaur set the pace up front.

"I am here to say, 'I am straight, hear me roar!'" said Mark Sahady, vice president of a group called Super Happy Fun America, which put on the parade. "Whether you are straight and part of the oppressed majority, or here as an ally supporting us, we welcome you to the greatest parade in the history of the world!"

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But the marchers were met by even more left-wing counter protesters, numbering more than 1,000, turning the event into competing demonstrations. The entire length of the parade's route was flanked with fencing, but the demonstrators followed alongside the whole way en route to City Hall.

Protesters, including many who identified with the anti-fascist group antifa, shouted "Nazi scum!" Some greeted the straight-pride marchers with their middle fingers and yelled expletives. Many LGBTQ advocates protested as well. Other people just stopped to see what was going on.

"Boston doesn't want you!" one man yelled. "We outnumber you!"

A massive contingent of police, including extra officers from neighboring cites, was present throughout, often getting in between the competing sides. They wore helmets, held gas masks and some had military garb. The police presence was so large, and fencing so vast, that many marchers struggled to make their way inside the plaza outside City Hall for the rally that followed the one-hour parade that stetched one mile.

Some counter protesters confronted police, who at one point appeared to use pepper spray on a group of anti-parade demonstrators.

Thirty-six people were arrested for a range of different charges, according to Boston police Sargent Detective John Boyle. He said four officers sustained injuries that were not life-threatening.

The parade's organizers, led by three straight Massachusetts men involved in Republican politics, said the parade was inspired by the "identity politics" of the left. Straight people are the "oppressed majority," they said. The event mocked "Pride" parades typically associated with LGBTQ advocacy.

Conservative commentator Milo Yiannopoulos served as the parade's grand marshal. But by the time he and other speakers took the stage outside City Hall, the counter protesters had multiplied while the straight-pride marchers had reduced considerably from their original size.

"Today, we are showing them that their hate cannot stop us!" Sahady yelled from the stage, directing his comments to the counter protesters on the other side of the fence separated by police officers. "We shall overcome. Free speech!"

Organizers rallied supporters to "fight against heterophobia in our modern society" and to "add an S to LGBTQ for Straight!"

"Spectacular," John Hugo, president of Super Happy Fun America, said when asked how he thought the parade went. "Better than we thought." Hugo, a former Republican congressional candidate, lost badly to U.S. Rep. Katherine Clark, D-Mass in 2018. Sahady is a member of the right-wing group Resist Marxism, who has organized several right-wing demonstrations in the past.

"We love being straight," Hugo said. "We love being pro-creators and having relationships between men and women. We think it's natural and it's wonderful. We're supporters and it's our sexual orientation. That's all. Nothing complicated."

Some marchers flew in from other states.

"I'm here to take a stand. I love Jesus and I love godly values," said Teresa Richenberger, of Kilgore, Texas. She complained that she's been asked by her school to "pick your identity" of her 4-year-old son.

"We're standing up today because we've been told to, 'Sit down, to suck it up, be quiet. You can't offend nobody,'" she said. "I don't want to offend no one. If you're gay, go be gay. That's OK. But I'm straight and I have a right to teach my son to be straight and to marry a woman when he gets older."

Karen Childress, who accompanied Richenberger to Boston, said two of her daughters are gay but they were OK with her attending the Straight Pride Parade. She said people "crossed the line" with homosexuality when it started to get "pushed on 5-year-olds."

"I always tell them the truth that God did not create them to be that way. They chose to live that lifestyle, and they're still in it," she said.

Among those who with the counter protesters was LB Lee, a Boston cartoonist, who accused the parade participants of seeking to roll back progress.

"I've lost housing, jobs and my schooling because of being trans," Lee said. "I don't like seeing the things that people like me fought for being co-opted by these guys.

"I think they are trying to roll back progress, and I don't think they're going to."

In Boston, long considered an LGBTQ-friendly city, the parade was widely condemned leading up to Saturday, with one of the sharpest rebukes coming from Emerson College. The private school in downtown Boston borders much of the parade's route

Emerson College President Lee Pelton, in a letter to students and faculty, slammed the parade as a "perversion" and "desecration of beauty, truth and generosity" led by "angry and misguided people."

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Super Happy Fun America organized the parade this spring, filing a discrimination complaint with the city after they said their proposal was initially ignored.

The city of Boston approved an application for the parade in June with Mayor Marty Walsh, a Democrat, arguing the city can't stop the parade from taking place just because people might disagree with the organizers' cause.

Walsh, who did not attend the parade and opposed its message, said permits to host a public event are granted based on "operational feasibility, not based on values or endorsements of beliefs." The Boston Police Department and licensing board each approved signed off on the necessary permits.

"If you want to see what Boston is all about, take a look at the events happening in our City this weekend that promote our values of inclusion, love of community and acceptance of all," Walsh said in a statement.

"As I've said, a 'Straight Pride' Parade won't overshadow the tremendous role Boston plays in the national movement for equality. We will continue to be a leader in the fight for civil rights."

Reach Joey Garrison on Twitter @joeygarrison.