Coverage of the Republican National Convention by all three major networks combined was watched by nearly as many viewers as tuned in to the results episode of America's Got Talent Wednesday night. NBC led the convention coverage with 4.5 million viewers, followed by CBS with 2.8 million and ABC with 2.6 million. But AGT grabbed 9.1 million viewers and was the highest-rated show of the night. CBS did score solidly with its Big Brother reality show, drawing 6.7 million viewers in the 8 00 p.m. hour and even managed to grab 5.5 million for a repeat of Criminal Minds at 9 00, which aired opposite America's Got Talent. Ratings for the major cable channels will not be available until Friday.