Wednesday morning in Washington began with a typical mix of visitors along the Lincoln Memorial Reflecting Pool: joggers, bikers, school groups, foreign tourists, a dancing majorette troupe from Carbondale, Pa. The Washington Monument, skinny and straight as six o’clock, was shimmering in the water.

But that was not what people were looking at, not today. After 104 years of alluring visitors with its reflections of some of America’s most majestic buildings, the attraction of the Reflecting Pool now is the pool itself.

All morning, tourists took selfies with the water. A visiting Irishman recorded a short film of it on his phone. People leaned over their bikes, debating the colors like art critics analyzing a Rothko painting. Nobody dared touch it, out of fear of being arrested.

The water is no longer the color of a putting green, but what color it was exactly — what the different shades might mean, whether there were cracks on the basin floor, how much this all cost — these were the things people were reflecting on.

“I guess it looks fine, but you can definitely see the algae,” said Allie Eardley, 40, who had promised her co-workers she would report on the state of the pool before she caught a noon flight back home to St. Louis. She added that she was more offended by President Trump’s demolition of the East Wing.

Over the past few weeks, the Reflecting Pool has truly lived up to its name, as the president, a good portion of the Washington press corps and large swaths of social media have reflected on it relentlessly. The drama began in April, when Mr. Trump announced on social media that he was “proud to be fixing the once beautiful Reflecting Pool” and that when he was done it would be “much more beautiful than the day it was built!”

Lucrative contracts were handed out to friends and donors, the pool was drained and refilled, and around June 10, it began turning green. Soon after, pieces of the resurfacing material on the bottom were peeling and the pool itself had grown ever more seasick. Dead ducks were found.

Mr. Trump blamed vandalism, “probably in the dark of night,” though he has presented no evidence for this. The Interior Department, which manages the site, said half a dozen people have been arrested, including a 67-year-old former U.S. Olympian who said he was charged with a federal crime after reaching into the water to feel one of the peeling pieces.

On Wednesday morning, the area around the pool was calm. There were quartets of National Guard soldiers standing in the shade here and there, but that is a familiar enough sight these days in Washington. Every few dozen yards along the side of the pool was a “nanobubble” machine at work, pumping ozone bubbles through long pipes that snaked along the pool floor. In the background, crews assembled tents and stands for the Great American State Fair, set to kick off Wednesday night with a Trump rally.

When it was finished in December 1922, the Reflecting Pool was intended as a place of dignity and tranquillity, inspired by the Grand Canal of Versailles and the reflecting pool before the Taj Mahal. It has in many ways lived up to this aspired stateliness, as a place where people found a unity they had been denied elsewhere: whether the 1939 concert by Marian Anderson, after she was barred from singing at Constitution Hall because of her race, or the 1963 March for Jobs and Freedom, where the Rev. Dr. Martin Luther King Jr. delivered his “I Have A Dream” speech.

But national divisions have arrived here, too. On July 4, 1970, as thousands gathered to listen to the evangelist Billy Graham as part of an “Honor America Day” celebration, a semi-clothed group of Yippies, who had assembled for a “pot smoke‐in,” marched through the reflecting pool and chanted antiwar slogans. That confrontation ended in tear gas and at least 34 arrests.

The current moment, to some of those who were studying the water on Wednesday, was similarly discordant.

“You sort of took the Reflecting Pool for granted,” said Chris Sadun, 51, who was visiting from Kansas. “Just like we assumed our courts and Congress were functioning properly.”

That an American institution that people had long taken for granted had become an expensive fiasco, tainted by accusations of corruption and questionable arrests, she said, “was emblematic of the entire Trump presidential experience.”

She said she would post a picture of the pool on a family chat but would not comment in the thread on what color it was, as she did not want to get political. For the record, she remembered the pool as looking a lighter blue in the past.

Albert Anthony, 41, a Louisiana man standing not far away, said the whole episode — the algae, the peeling surface, the greenness — was cooked up by the media. Just look at the water, right now. It isn’t green. “Fake news,” he said.

He declared the pool better looking than it had ever been, “cause Trump’s the best president we ever had.”

Between the two of them, it would be difficult to come up with a better reflection of the national mood.