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 adviser has become a major political problem. While the president passed up another chance Wednesday to express 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. "The extreme left is once again attempting to define the modern Democratic Party by rabid partisan attacks, character assassination and endless negativity," said Rep. Tom Reynolds, R-N.Y., chairman of the GOP congressional...