WASHINGTON -- When U.S. Rep. Brad Sherman found a moment alone with President George W. Bush at a recent White House holiday party, the Sherman Oaks Democrat homed in on the probability of Iran acquiring nuclear weapons. A few weeks later, at an Oval Office bill signing, Sherman again raised the issue, handing Bush a five-page memo detailing the steps he believes the administration should be taking. "I've had about 10 substantive conversations with the president, and every one of them has been about Iran," Sherman said. "I could talk to him about the Santa Monica Mountains, but that could...