Polarizing progressive Democrat David Hogg is wading into the New York City mayoral race to endorse Zohran Mamdani, the 33-year-old democratic socialist who is running second in the polls. 

Early voting is underway and Election Day is Tuesday.

Mr. Hogg, a survivor of the Parkland high school shooting in 2018, is fresh off of being forced out as a vice chairman at the Democratic National Committee after he released a plan to challenge what he describes as “out-of-touch, ineffective” congressional Democratic incumbents with younger and more progressive candidates.

Mr. Mamdani has a new video on his X account showing the pair meeting with voters in Washington Square Park. Text on the screen reads: “Now David Hogg is my best friend.”

“We’re really excited to support the campaign here to help make New York City affordable, help make sure that buses are faster and free at the same time, and that no New Yorker has to pay for child care,” Mr. Hogg says in the video.

The video shows several younger voters saying they plan to vote for Mr. Mamdami.

Mr. Mamdani is looking for a boost in a crowded primary field with former Governor Andrew Cuomo as the front-runner.

The New York City primary uses ranked choice voting, which allows voters to select their top five candidates. If one candidate gets more that 50 percent of first choice votes, they win. If not, the vote moves to a second round with the candidate receiving the least number of votes eliminated. The people who voted for the person who was eliminated have their second choice counted. The rounds of elimination and redistribution of votes continue until one candidate tops 50 percent.

Both the New York Daily News and New York Times have urged voters to avoid ranking Mr. Mamdani on their ballots to keep him from winning in a later round of counting. Polls have shown Cuomo with a roughly 10-point lead but receiving under 50 percent in the first round. 

Mr. Mamdani is facing criticism over his refusal to condemn an anti-Israel slogan, “Globalize the Intifada.” He also has been attacked by moderate Democrats and some Jewish groups throughout for his views on Israel, including his refusal to acknowledge Israel’s right to exist as a Jewish state.

Rising antisemitism and the war in Gaza have emerged as key issues in the race.