It’s one of the few points not up for debate this election season: TV coverage of the typically uneventful U.S. political conventions drew record-breaking audiences. 
Nearly two-thirds of all U.S. households (64.5%) — 120.1 million people age two or older — watched at least one of the 2008 political conventions, according to a new analysis released Thursday by Nielsen. 
Viewership levels for the Democratic and Republican conventions were essentially even, with about half of all U.S. households watching each.  Overall, 15% of all homes tuned in to the Republican National Convention only, while 15.7% …