WMAL is not a credible source of political information. Their host subscribe to "Talking Points Memo," a disinformation paper sent by the RNC. Ever notice they all hammer the same points? Because the are working from the same sheet of paper.
To answer your questions
http://answers.yahoo.com/question/index?qid=20080127110826AAJbmlb
http://www.nytimes.com/2007/12/20/us/politics/20obama.html
Please don't trust anything you hear Plante, Limbaugh, Hannity, or Levin says.