Sen. Kirsten Gillibrand (D-N.Y.), who struggled to gain traction in a crowded field, ended her presidential run Wednesday, a further winnowing of the Democrats hoping to take on President Trump in 2020.

Gillibrand’s decision comes after news that she’d fallen short of meeting the requirements for the September Democratic primary debate.

In the past two weeks, Washington Gov. Jay Inslee, former Colorado Gov. John Hickenlooper and Rep. Seth Moulton of Massachusetts left the race. Twenty Democrats remain and only half will be on the debate stage.

Gillibrand, 52, announced her departure in a two-minute video that is mostly a montage of her time on the campaign trail. In the video, the senator says she will focus her energy on uniting Democrats to defeat Trump.

“It’s important to know when it’s not your time,” she says in the video.

Despite her early entry into the race with an exploratory committee in January, Gillibrand could never break 1 or 2 percent in national polls. As one of four female senators in the race, she needed a standout moment that never came.

“My friend @SenGillibrand is a brave voice on some of the most critical issues facing our country today — from childcare to sexual assault. She is a champion and I know she’s not done fighting for women and families everywhere,” tweeted Sen. Kamala D. Harris (D-Calif.), a presidential hopeful.

Gillibrand branded herself “the best candidate for women” and hoped her record on women’s rights would resonate with female voters. She has long been an advocate for victims of sexual misconduct, even when it put her at odds with her own party.

In 2017, Gillibrand was the first Democratic senator to call for the resignation of former senator Al Franken of Minnesota over allegations that he behaved inappropriately with women. She shocked and angered some in the Democratic base the same year when she said in an interview with the New York Times that former president Bill Clinton should have resigned over his affair with White House intern Monica Lewinsky.

Gillibrand replaced Hillary Clinton in the Senate in 2009 when Clinton became President Barack Obama’s secretary of state. Gillibrand had been close to the Clintons, and some saw her comments as a betrayal of that relationship.

The senator also may have struggled to amass donors and voter support in an increasingly liberal Democratic Party because of the conservative positions she held on guns and immigration earlier in her political career.

Gillibrand raised $2.3 million in the second quarter of 2019. She had $8.2 million in her campaign coffers, but most of that was transferred from her Senate campaign account. South Bend, Ind. Mayor Pete Buttigieg (D) raised $24.8 million in the same period.

Gillibrand came to Washington via the House in 2006 to represent a conservative Upstate New York district.

Though Gillibrand focused most of her campaign message on Trump, she did go after former vice president Joe Biden directly during the second debate, hitting him for a 1981 opinion piece he wrote that she said degraded working mothers.

“You said women working outside of the home would lead to the deterioration of family,” Gillibrand said. “My grandmother worked outside the home. My mother worked outside the home.”

When Biden was asked by reporters about Gillibrand’s departure from the race, he offered only praise.

“She’s smart as hell and she had a lot to contribute. It’s hard. It’s hard when you have so many people in the race,” Biden said after a speech in South Carolina. “She’s — she’s a caliber person and I hope that means she’s going to stay deeply involved in what she’s doing, because if I’m lucky enough to be one of the people that gets elected — if I’m the person that’s elected — I would go to her for help.”

Trump reacted to the news with sarcasm.

“A sad day for the Democrats, Kirsten Gillibrand has dropped out of the Presidential Primary,” Trump tweeted. “I’m glad they never found out that she was the one I was really afraid of!”

Gillibrand just won reelection to the Senate in 2018, so she will not have to run again until 2024 — when there will be another presidential contest.