CNBC said its Wednesday-night telecast of a debate among Republican candidates for U.S. President lured an average of 14 million viewers, making it the most-watched broadcast on the NBCUniversal-owned cable outlet in its history.CNBC’s audience for the telecast was significantly lower than the crowds lured by Fox News Channel and CNN for similar events. A Republican debate broadcast in August by Fox News attracted an average of 24 million viewers, while a Republican debate broadcast in September by CNN won an average of 23.1 million viewers.For CNBC, however, the numbers were meaningful. The network said it the broadcast of the...