I'm not even sure our local Nashville ABC filly-ate runs Nightline at all - and I'm too lazy to go to their website to find out. I do known that they run back-to-back Friends syndie episodes after the late news, and then they run Jimmy Kimmel for another hour. So if they do run it, you can bet virtually no one is watching.
A lot of thought was given not too long ago at ABC of dumping Nightline altogether, but the network decided that the show was, in their words, "too important." Even though its ratings are virtually nil, the net (a) wants the "prestige" of airing the show and (b) wants to reward Koppel for his years of allegiance to the left party.
Michael