U.S. liberal groups push congressional Democrats on Iran nuclear bills

By Patricia Zengerle WASHINGTON (Reuters) - U.S. progressive groups rallied on Thursday to persuade Democratic senators not to support a bill giving Congress a vote on a nuclear deal with Iran, echoing the White House's insistence that the measure could blow up delicate negotiations. Five groups - CREDO, Daily Kos, Democracy for America, MoveOn.org Political Action and USAction - sent a letter warning Senate Minority Leader Harry Reid, Minority Whip Richard Durbin and seven other Democratic U.S.