There's something wrong here. Five years ago was 1999 -- a year before GWB ran for President, and two years before he took office. Why would Mapes try to save the world from something that didn't even exist?
actually makes sense. If she was trying to prevent the election of Bush in 2000. She would have probably worked tooth and nail to keep Reagan from getting elected into office during the 1980's.
Since the "likely suspects" of who is running for office is generally known, it is highly likely she started reasearch back then before files before everone else started digging through the same background data. IOW she probably knew about the DUI loooooong before Bush even won the primary but they held it back for October.