WASHINGTON (AP) - Republicans are nervously watching the fight over Karl Rove's involvement in a news leak that exposed a CIA officer's identity, fearing that President Bush's chief political adviser is creating a credibility problem at the White House. While the president passed up another chance Wednesday to directly voice confidence in his deputy chief of staff, his political team engineered a series of testimonials from members of Congress who praised Rove and condemned Democratic critics. And Bush's press secretary, Scott McClellan, told reporters the president has confidence in his longtime confidant. "The extreme left is once again attempting to...