Jewish donors and fund-raisers are warning the Obama re-election campaign that the president is at risk of losing financial support because of concerns about his handling of Israel. The complaints began early in President Barack Obama's term, centered on a perception that Mr. Obama has been too tough on Israel. Some Jewish donors say Mr. Obama has pushed Israeli leaders too hard to halt construction of housing settlements in disputed territory, a longstanding element of U.S. policy. Some also worry that Mr. Obama is putting more pressure on the Israelis than the Palestinians to enter peace negotiations, and say they...