ON THE DELAWARE RIVER — Allison Butler held an American flag above her head and belted out the chorus to Lee Greenwood’s “God Bless the USA,” wearing a Trump 2020 bathing suit while on a boat floating down the Delaware River.

The boat carrying her Saturday was one of several hundred that formed a flotilla on the waterway between Philadelphia and New Jersey, one of many such boat parades that have popped up across the country in recent months — much to President Donald Trump’s delight.

“Trump 2020!” Butler shouted across the Delaware as the song ended.

The parade cruised from near Dave & Buster’s in Philadelphia, just north of the Benjamin Franklin Bridge, and headed south to near West Deptford under clear skies and on choppy waters churned up by the deluge of motorboats.

Trump boat parades have taken off since they started with supporters in Florida in May, with the president unable to hold his signature large rallies because of the coronavirus pandemic. They have since spread to Arizona, California, Michigan, and South Carolina.

As polls have pointed to a clear erosion in Trump’s political standing in Pennsylvania and other battleground states amid his mishandling of the pandemic, he has relished the spontaneous nautical pep rallies. He often tweets out thanks for them and holds them up as a sign of enthusiasm for his campaign compared with that of presumptive Democratic nominee Joe Biden.

Parades this weekend were also planned on Lake Charles in Louisiana and on Long Island, where a TrumpStock boat parade coincided with a fund-raiser Trump was attending in the Hamptons.

Saturday on the Delaware River, there were boats with cardboard cutouts of Trump, boat-riders in Trump masks, boats decorated with his name or likeness, and a ton of flags with various slogans: “Make America Great Again,” “Don’t Tread on Me,” and “F— Your Feelings: Trump 2020.” The Trump campaign said in late May that the biggest sellers on its website were blue boat flags bearing the president’s last name.

A small handful of people protested along the banks of the river, including a man in West Deptford who wore a Trump mask and a prison inmate outfit, and carried around a golf club, mocking Trump’s penchant for golfing during a time of national crisis.

Rick Bodine had his 26-foot formula motorboat plastered with the word TRUMP in preparation for Saturday’s parade. He was there with his wife, Jessica, and a group of friends.

“Go Trump 2020!” Bodine, 48 of Bensalem, said as someone else on the boat shouted, “Buy American!”

Bodine works as an air-conditioning and heating contractor and said his business has taken off in the last four years, which he credits to Trump. “Freedom and work,” Bodine said. “I’ve been thriving in the last four years.”

Passengers on Bodine’s boat, named Karma Seas, said they weren’t concerned with polling that shows Trump sinking. “There’s a lot of us keeping our mouth shut but voting the way we should vote,” one said.

“My mom’s a Democrat,” Bodine agreed. “And she voted for Trump and nobody knew she did — until now.”

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But Saturday was not a silent display of support. It was loud — with motors roaring and country music blasting, taking on the feel of a river tailgate as people sun-lounged and danced on boat decks, honking horns and raising drinks at one another.

“It’s great to see all the Trump flags flying,” said Tony Cook, of Salem, N.J., sipping on a Bud Light. “It’s good to see everybody out and about for a good cause. Seems like a lot of positive energy.”

Trump “has done nothing but good as far as I’m concerned,” Cook said. “And he’s not a politician. He’s for us.”

Keith Mease, of Carneys Point Township, N.J., summed up the afternoon like this: “Today’s about America.” He marveled at the turnout, noting that Trump has drawn crowds for rallies and tailgates over the last four years, not just in the three months before Election Day.

“I’ve never seen this much external support, year-round, for a president,” Mease said.

The Trump campaign has been leaning into the boat parades. And for good political reason.

Boaters happen to be concentrated in some swing states, making the kind of exposure the parades get a boon for the campaign. Florida is first in boat rental licenses, according to the National Marine Manufacturers Association. Michigan ranks sixth and Pennsylvania is 10th.