The headache started in the morning. It was a Thursday last June, and Jeff Zucker, president of CNN Worldwide, was working on the final preparations for New Day, the morning show he was set to debut four days later. From the moment Zucker took over CNN in January 2013, he had been focused on getting the morning right. He was a morning-television savant, after all, having led the Today show on a storied run of ratings dominance. And CNN’s early show, Starting Point With Soledad O’Brien, had become a symbol of the network’s slide from cable-news pioneer to industry laggard. O’Brien drew just 260,000 viewers, compared with more than a million people who watched Fox & Friends and some 450,000 viewers of Morning Joe on MSNBC.