ATLANTA (AP) — He's an ardent supporter of Israel and a megabillionaire casino mogul whose empire is under federal investigation. And he's the self-proclaimed "richest Jew in the world."Sheldon Adelson is also, far and away, the biggest patron of Newt Gingrich's surging presidential bid.Adelson and his wife, Miriam, have pumped $10 million into a political action committee backing Gingrich. Campaign finance experts say the two $5 million contributions are among the largest known political donations in U.S. history.No other candidate in the race for president appears to be relying so heavily on a single donor. It's been made possible by last year's Supreme Court ruling that recast the political landscape by stripping away restrictions on contributions.