Bernie Sanders in Washington Square Park View Full Caption

GREENWICH VILLAGE — A surrogate for Bernie Sanders told a crowd of the presidential candidate's supporters at a large rally in Washington Square Park Wednesday night not to elect "corporate Democrat whores who are beholden to big Pharma and the insurance industry."

Dr. Paul Song's use of the word "whores" seemed to surprise some in the estimated 27,000 people who had packed into the park to support Sanders.

On Twitter, leading New York politicians admonished the campaign, urging them to denounce the statement.

This level of rhetoric is simply unacceptable. Let's see if it is denounced. #ImWithHer #EstoyConElla https://t.co/M0QYaNoNXw — Melissa MarkViverito (@MMViverito) April 13, 2016

Sanders took to Twitter Thursday morning to denounce Song's comments.

Dr. Song's comment was inappropriate and insensitive. There's no room for language like that in our political discourse. — Bernie Sanders (@BernieSanders) April 14, 2016

Also, Song tweeted an apology.

I am very sorry for using the term "whore" to refer to some in congress who are beholden to corporations and not us. It was insensitive. — Paul Y. Song (@paulysong) April 14, 2016

Washington Square Park was closed down Wednesday as fans of the Vermont Democrat arrived early for the rally.

Emptiest I've ever seen Washington Square Park pic.twitter.com/SGW5urE1Yp — Danielle Tcholakian (@danielleiat) April 13, 2016

Emily Petras, 21, of New Jersey, arrived just before noon. This election will be her first time voting.

“It’s good to have a candidate you can be excited about” as a first time voter, she said.

Doors to the event opened at 5 p.m., with entrances at the southwest and southeast corners of the park. Admission was first come, first served.

Waiting for Bernie https://t.co/SZf3dSkRJZ — Danielle Tcholakian (@danielleiat) April 13, 2016

Indie band Vampire Weekend performed for supporters, and cheered the union members on strike from Verizon who had come out to support Bernie — though frontman Ezra Koenig had to disappoint one member who wanted to hear a Led Zeppelin song.

The band didn't know any Led Zeppelin songs, Koenig said. He promised to learn one for "next time."

Koenig and his bandmates are alumni of Columbia University, and were backed up Wednesday night by the college's all-female a capella group, the Metrotones. He acknowledged the irony of performing in their rival school's front yard, with the New York University campus all around them.

"But if there's one place to put aside all the bourgeois rivalries of private universities, I think it's a Bernie Sanders rally," he said. "So f— all that."

"Shout-out to CUNY," he added, referring to the city's public university.

Other celebrity speakers at the rally included Tim Robbins, who railed against the media and the Democratic Party and recalled protesting the Vietnam War in the park. Director Spike Lee also attended.