This theme has been used for coverage of the 1996, 1998, 2000 and 2002 elections. Generally the broadcast networks go all out for general elections and special graphics, sets and themes are to be expected. This theme is composed by Non-Stop Music, which had already done some bumpers for Today and themes for MSNBC.
Welcome!
Network News Music is a website by Victor Vlam, who holds the Guinness World Record for the largest collection of news music. 1,876 hours, 2 minutes and 52 seconds. News music is rarely heard without voice-overs or fade outs to commercial, yet it leaves an impact on many people. Founded in 2002, this site is a museum for TV news themes past and present.
I forgot that this theme was also used as a bumper on NBC Nightly News.