"The Star Spangled Banner" has an insipid melody that is also difficult to sing. Its lyric is archaic and, in the version most frequently performed, annoyingly incomplete. Let's face it, it's just a terrible song.
"One Nation Under a Groove," in contrast, has an awesome dance beat and an uplifting lyric. It communicates a message of inclusion, unity, and the primacy of the one. Imagine a ballpark full of people singing "One nation, we're on the move, nothing can stop us now" and try to pretend that would not be awesome. You can't!
Changing our national anthem from the bellicose "Star Spangled Banner" to the pacific "One Nation Under a Groove" will also announce to the world that ours is a peaceful nation, not a hostile one. This change could well promote world peace.