Why are the likes of Helen Thomas and Gregory tolerated at the White House press conferences?

(My Original Blog Post: http://www.latesttrendsguide.com/?p=3656)

Their partisan presence adds nothing and detracts from the purpose of the press being there
I am not referring to the questions, I am referring to the partisan statements that are made for no reason other than to further a cause - that has no value in a press conference.