Former President Barack Obama’s treasury secretary says he is worried that mayoral candidate Zohran Mamdani will ruin New York City if he wins."The policies that he’s outlined are not policies that are good for New York. He’s running for mayor of New York, and I worry deeply, having spent most of my life in New York, about a city that I call home, you know it," Jack Lew, former treasury secretary, said Tuesday on CNBC’s "Squawk on the Street." "I see a similarity between the kind of policy solutions to the left and the right, and, you know, that satisfy populist sentiment," Lew added. "Don’t always go through the filter of, ‘Do they work?’ I don’t think they work. And I think that’s a problem."CITY-RUN GROCERY STORES, DEFUNDING POLICE, SAFE INJECTION SITES: WHAT TO KNOW ABOUT NYC'S NEXT POTENTIAL MAYORMamdani, a 33-year-old state assembly member from Queens who was born and raised in Uganda, is a proud democratic socialist. He has recently discussed raising corporate taxes to pay for his idea to "Trump-proof" New York City."We're talking about corporations that are making millions of dollars, not in revenue, but in profit," Mamdani said during a June 11 episode of "The Breakfast Club" radio show. "And the second is taxing the top 1% of New Yorkers. We're talking about people who make a million dollars a year or more, taxing them just by a flat 2% tax increase." During the conversation, Mamdani acknowledged that some, like rapper 50 Cent, don’t approve of his ideas. "I know if 50 Cent is listening, he's not going to be happy about this," he added. "He tends to not like this tax policy, but I want to be very clear, this is about $20,000 a year. It's a rounding error. And all of these things together, they make every New Yorker's life better, including those who are actually getting taxed now."NEW YORK DEMOCRAT SAYS MAYORAL CANDIDATE ZOHRAN MAMDANI 'TOO EXTREME TO LEAD'Mamdani has also come under fire for a campaign policy document that directly calls for moving NYC’s tax burden onto "richer and whiter neighborhoods."But Lew, who also served as the United States ambassador to Israel from 2023 to 2025, says he is concerned about Mamdani’s policies, and how the state would respond. "One of the things I’ll say about New York is that New York is not an entirely independent governing entity," Lew said. "Many of the policies have to be approved by the state legislature or governor," he added. "So it’s a process where you have more centrist political voices that will still be very much in a position to determine whether or not different tax and spending policies can take effect. You know, I think the Democratic Party is well served by building the center out. And that means appealing to the center left and the center right. I think going to either extreme in either party tends to polarize the country. So that’s my own personal view. But I really can’t speak to the party politics part of it."