Manhattan congressional candidate Jack Schlossberg says he supports the effort to block arms sales to Israel and claims that the US has already lost the war in Iran. The grandson of President John F. Kennedy said during a recent candidates forum at the Stephen Wise Synagogue on the Upper West Side that he supports the resolutions advanced by far-left Vermont Sen. Bernie Sanders to deny Israel $440 million in bombs and military equipment. Forty Democratic senators voted for the ban on equipment, but seven Dems sided with Republicans to defeat the measure — including New York Sens. Chuck Schumer and Kirsten Gillibrand. Democratic congressional candidate Jack Schlossberg speaking at a forum at Stephen Wise Free Synagogue in Manhattan on May 6, 2026. Lev Radin/ZUMA / SplashNews.com A second measure, which sought to block the sale of 1,000-pound bombs to Israel, was defeated by a greater margin, 36 votes in favor and 63 against.…