Answer:  Radio and Television Transcripts

Go to Lexis-Nexis @ http://www.smcvt.edu/library/resources/databases.htm#le 

Open Lexis - Choose News - Choose Transcripts 

Other sources 

CNN http://gwu.edu/~gprice/speech2.htm 

NPR Radio Archives in Audio - http://www.burrelles.com/nprframe.html 

Television News Archives - http://www.burrelles.com/nprframe.html
You may view abstracts of news programs back to 1968, and may order videos of the broadcast