National Guard members patrol the Lincoln Memorial Reflecting Pool in the Trump administration’s battle against algae, June 19, 2026.Mark Schiefelbein/AP
Like the Strait of Hormuz, the Lincoln Memorial Reflecting Pool has exposed the limits of the power of the United States of America: President Donald Trump is also losing his war against algae.
In the face of thriving algal blooms and peeling “American flag blue” paint, the National Park Service on Monday began draining the pool for repairs. A contractor performing the work told E&E News that those repairs would not be done by July 4. The prior rehab, which Trump rushed to complete via no-bid contracts and more than $14 million in spending so far, has failed.
Trump, though, has blamed the problems on vandalism. And he has dispatched a hodgepodge army of law enforcement to protect the pool from “Radical Left Lunatics,” who he has said should face “Years in jail!”
Observing the action at the pool over much of the long weekend, we did not spot any antifa dumping algae, as MAGA conspiracy theorists allege. The hot temperature, shallow water and flawed filtration system means the green Scenedesmus algae can conquer the pool without human help.
There were, however, lots of cops. Walking around the pool at about 4 p.m. ET on Saturday, we counted at least seven US Marshals, some in “fugitive task force” tactical gear. They were supported by around 30 local police officers, volunteers who said they had been deputized for 30 days by the Marshals Service to help provide security for 250th anniversary celebrations. They came from Oklahoma City; Idaho Falls; Sarpy County, Nebraska; as well as Ontario, Wayne and Monroe counties in New York. They were mostly standing in the shade, and friendly. Some were hoping to catch Nationals game on a day off. They seemed sort of bored.
The cops were coordinating with a handful of Park Police officers and maybe a dozen National Guard troops from Georgia and Louisiana, who were patrolling the pool in small groups. Over the last few days, agents with the Drug Enforcement Administration and Immigration and Customs Enforcement have also appeared poolside.
On Saturday, there were issues with radio frequency connections, so a mounted Park Police officer rode a white horse between groups of officers to share information on potential threats to the pool. He was less chatty than the volunteer officers, but he said that the horse’s name was Delilah, and that she was 21 years old.
The officers explained that visitors could take paint chips, but peeling paint still attached was forbidden.
In the pool, seven or so Park Service employees, wearing boots, waterproof overalls and NPS hoodies for the sun—it was about 86 degrees and sunny—were vacuuming up algae using pumps attached to long poles. (They had by then given up pouring in hydrogen peroxide.) Machines were pushing what looked like white foam into the water: the “high-tech nanobubble ozone technology” that the administration has claimed would kill the algae. Generators powering the pumps hummed loudly as green-tinted water poured out into drains on the Mall.
Another dozen or so uniformed Park Service employees looked on from the shade. On the north side of the pool, a duck and eight ducklings sat on the edge of the water. A park ranger sitting nearby said neither the algae nor cleaning efforts would hurt them.
From the steps of the Lincoln Memorial, tourists took pictures of the scene. A band, in traditional Polish garb, prepared to play folk music for a holiday marking the summer solstice. A tourist shop nearby sold $18 water bottles with stickers advertising Freedom 250, the semi-private group Trump is using to organize highly personal celebrations linked to the 250th anniversary.
By the pool, a person in a pink frog costume brandished a “Team Algae” sign and heckled two National Guard troops. “Let’s go algae, let’s go,” the frog chanted, along with something about “pond scum.”
A small boy, in an ice cream cone shirt, asked his mother if the critics were protesting the algae. “No,” she answered. “They’re mad at the president.”
“Did he mean to grow the algae?” the boy asked. “No,” she said. Then they went to get ice cream.
Near one of the drains, an older couple, maybe in their sixties, picked through the grass nearby for loose pieces of blue paint, having first checked with the Park Police that doing so was permissible.
The officers explained that visitors were allowed to put their hands in the water. They could even take paint chips that were already detached. But peeling the paint still attached to the pool was forbidden.
The administration said Monday that Park Police have made five arrests and issued five citations for alleged vandalism. But an officer on the scene Friday evening said that they had also detained more than 20 people, in many cases without further action, for suspected pool tampering.
On Sunday afternoon, Trump posted that he had “just inspected the pool” and decried the vandalism he said he observed.
“WOW, who would do such a thing?,” Trump wrote. “SICK, DERANGED PEOPLE!”
The president, though, didn’t view the pool from the ground. He appears to have formed his impression from a helicopter as he returned to the White House from Camp David.
Down below, one of the ducklings was photographed floating dead in water. (Experts note that most ducklings in the wild die before reaching maturity, so it’s not clear whether the algae or chemicals used to clean the pool were to blame.)
On Saturday around 5:30 p.m., the radios of the marshals we were walking past barked. “One male, black shoes, white socks, currently being detained,” someone said. “Eleven Charlie moved to intercept.” Two officers sped away in a golf cart.
Across the pool, Delilah galloped toward a group of National Guard troops surrounding a young man, in white socks, seated with his ankles crossed on the grass by the north side of the pool. A Park Police cruiser, siren on, pulled up.
By the time we made it around, a half dozen of the local police, seven National Guard troops and a couple Park Police officers surrounded the suspected vandal in a semi-circle, facing a small crowd of onlookers.
After a few minutes, they let the guy go. He declined to give his name. But he said he was from Indiana, and that he had stuck his hand in the water and pulled out a piece of floating paint. The officers had suspected that he pulled it off. He received a citation, he said. He walked off with his family, looking embarrassed.
The cops dispersed. There was a big pile of poop where Delilah had stood. In the water, the feds kept vacuuming the algae.
