Oprah Winfrey WHITE HOUSE — Just days into 2018, the race for the U.S. presidency in 2020 is already making headlines. When asked Monday aboard Air Force One about a potential high-profile general election opponent to President Donald Trump — namely, self-made billionaire media proprietor and philanthropist Oprah Winfrey — deputy White House spokesman Hogan Gidley responded, “We welcome the challenge, whether it be Oprah Winfrey or anybody else.” Winfrey, 63, however, is not running — at least, officially. But her Sunday night speech at the Golden Globe awards show unleashed immediate and intense media speculation about a candidacy in 2020, presumably as a Democrat. “I don’t know if he saw it,” Gidley responded to a reporter’s…