Bunny ears. Rain slickers. Sixty-four thousand hard-boiled eggs.

Under rainy skies, President Biden on Monday hosted the White House Easter Egg Roll, a tradition so wholesome and old-fashioned that it often simply transcends Washington politics.

“Easter reminds us of the power of hope and renewal, sacrifice and resurrection, but mainly, love and grace toward one another,” Mr. Biden said from the White House balcony, where he stood between two enormous Easter Bunnies.

But this year, even before the skies opened on the children who were gleefully rolling eggs down the White House lawn, the 146-year-old tradition was caught up in a partisan storm.

In the days leading up to the event, Republicans seized on guidelines for the annual egg decorating contest that prohibit religious symbols on the entries — even though the rule has existed for decades and was enforced by Mr. Biden’s predecessors.

Mr. Biden’s political opponents also slammed the White House for commemorating Transgender Day of Visibility on Easter Sunday. The day of visibility has been held on March 31 for the past 15 years; this year, that date happened to be Easter Sunday.

Mr. Biden briefly addressed the controversy when asked about House Speaker Mike Johnson saying that it was “outrageous and abhorrent” for the White House to observe the day on Easter.

“He’s thoroughly uninformed,” Mr. Biden said.

For the most part, the Republican-stoked culture war meant little to those who turned out for the event. Before he joined the crowd on the lawn, Mr. Biden welcomed everyone and introduced the big attraction.

“Say hello to our Easter Bunnies,” he said. “Come on up, bunnies. Get up here so they can see you. Come on, get in there. Pretty big bunny, huh?”

The White House estimated that roughly 40,000 people would attend, its highest attendance ever.

Asked what she was looking forward to most at this year’s Easter Egg Roll, Kylie Hughes, a 7-year-old from Waldorf, Md., said, “I like hearing Joe Biden talk.”

The president took pictures with children and families, and even helped console a young girl who, frustrated by her form, began to cry until the president joined her in rolling her egg.

“It’s really about kids, and Easter and celebrating,” said Nikki Santos, a member of the Coeur d’Alene tribe who lives in Washington, D.C., with her 7-year-old daughter. “And you definitely feel that positive, happy energy today.”

Jill Biden, the first lady and a teacher of 30 years, made the theme of the event “EGGucation” and transformed the South Lawn and Ellipse into a school community, including hot air balloons and activity stations. She hosted families in a “reading nook,” where she read “Brown Bear, Brown Bear, What Do You See?”

“I’m a teacher, so I love any time when we can turn the White House into a classroom,” Ms. Biden said. “And that’s what we’re doing today.”