I hate beating up on David Shuster because he's one of the better ones, but here's yet another example of how deeply the press internalized the notion that impeachment/Monica madness caused a drop in Clinton's popularity. His popularity soared during this period, something the Washington press could never quite get themselves to understand.
Clinton was unpopular in 1994, that was basically it. Right before Monica madness hit, Gallup polled Clinton at 59. Subsequently, the poll never fell below 58 (hitting that number once) throught the entire impeachment saga. His lowest job approval rating throughout his entire second term was 53, and his highest disapproval was 42.