Four states are holding primaries on Tuesday, including New York, with several closely watched congressional races, and South Carolina, with a Republican runoff in the governor's race after no candidate won majority support in the primary earlier this month. New York City Mayor Zohran Mamdani's influence will be tested at the ballot box, since he endorsed and even cut an ad for his three preferred candidates that ran during the Knicks playoff games. He also spoke at a rally over the weekend on behalf of the three. Voters in Manhattan's wealthy and powerful 12th District will also be selecting a Democratic nominee. Voters in Utah and Maryland are casting votes in primaries in their states, too. Here are the key races to watch on Tuesday: New York's 10th DistrictDuring last year's mayoral election, Mamdani and former New York City Comptroller Brad Lander cross-endorsed each other during the ranked-choice voting process. After Mamdani's win, Lander threw his hat in the ring to challenge incumbent Rep. Dan Goldman, who served as one of the Democrats' lawyers in their first effort to impeach President Trump. Goldman won the district, which includes Lower Manhattan and parts of Brooklyn, in 2022 after a crowded, expensive Democratic primary. (An heir to the Levi Strauss fortune, he is one of the wealthiest members of Congress.) But since then, Goldman has advocated for more support for Israel than other progressive Democrats, which Lander said inspired him to run. Both Lander and Goldman are Jewish, but their differing views on Israel's actions in Gaza have made this one of the dominant issues in the race.Mamdani is backing Lander, as are Sen. Bernie Sanders and Rep. Alexandria Ocasio-Cortez. New York Gov. Kathy Hochul and House Minority Leader Hakeem Jeffries are supporting Goldman. Polling has shown Lander has an edge going into the primary, though such surveys may be inconsistent. The district is heavily Democratic, so the winner of Tuesday's primary is favored to win in November.