By WILL WEISSERT WASHINGTON — Both major presidential candidates are making appearances Thursday meant to fire up their core supporters, with Vice President Kamala Harris participating in a livestream with Oprah Winfrey and Donald Trump attending an event with prominent Jewish donors before addressing a gathering of the Israeli-American Council. Winfrey, who has endorsed Harris and spoke at the Democratic convention in August, is set to host a two-hour “Unite for America” nighttime streaming session in Michigan with Harris that organizers say aims to highlight dozens of grassroots groups backing the vice president. Trump will be in Washington to address a “Fighting Anti-Semitism in America” evening event with Miriam Adelson, a co-owner of the NBA’s Dallas Mavericks and widow of billionaire casino magnate Sheldon Adelson, who founded the Las Vegas Sands casino and was one of the Republican Party’s largest donors. Trump will also speak before the Israeli-American Council, a nonprofit long backed by Sheldon Adelson as well as Haim Saban, a major donor to President Joe Biden and Democratic causes.