Republican lawmakers asked increasingly tough questions today as they held another day of hearings to investigate, in the words of Rep. Darrell Issa (R-California), Hillary Clintons suspiciously high poll numbers and what can be done to make them lower. With the help of Fox News, we have brutally attacked Hillary Clinton for months, and yet she remains more popular than ever, Rep. Issa said. This committee needs to know how that happened, and how we can keep it from happening in the future. Rep. Issa pointed to recent polls showing the former Secretary of State trouncing every potential G.O.P. Presidential candidate, even a skinnier version of Chris Christie. We demand an answer to one simple question, he said. What does Secretary Clinton know that none of us knows? In his boldest allegation of the day, Rep. Issa accused Secretary Clinton of cynically using her post as Secretary of State to become wildly popular with the American people. I invite her to these hearings to answer those charges, he said. Wrapping up for the day, Rep. Issa warned the former Secretary of State that he was just getting started: Once we Republicans decide to investigate someone, we dont stop. If Secretary Clinton doesnt believe me, she should ask her husband. 