Rush always states that his show is about himself stating his opinions. His "slams on the man" is because McCain is running for the President of the United States, and is claiming to be a conservative. Rush is a political commentator that is commenting about McCains history when it comes to taxes, education, nanny state, free speech, immigration, etc. Rush is also commenting on Obama, Hillary McCain and others. Rush is a political commentator that is a conservative commenting and giving his opinion on those running as President. Rush is doing his job, no one should be surprised.
And doing it quite well, we should add.