To say that Chris Harrison has emerged as The Bachelor's breakout star implies that there was a time in which he wasn't. Which is sort of false: as the host of the show, he's more visible than any star or contestant has ever been. That being said, he's gotten more and more attention during the ten-plus years he's hosted the franchise, especially during the past few seasons.
In 2012, Harrison announced that he and his wife of 18 years were getting a divorce. While producers of the show (of which Harrison is one) likely worried that Harrison's divorce would make viewers doubt his ability to guide the tortured souls on The Bachelor and Bachelorette down the path to love, they worked hard to make sure Chris was still viewed as a sage. He says nothing negative about his ex-wife, instead showering her with praise in any interview he gives. (Though has been rumored to be dating a former Bachelor contestant.) He still sits and chats with Bachelors and Bachelorettes about their feelings just as he always did. And this season, as the hearts of viewers everywhere have been trampled on by clueless wonder Juan Pablo, Harrison has become more important than ever. No longer confined to the opinions expressed in his blog posts for Entertainment Weekly, Harrison has shown himself to be far more credible than he appears in his brief appearances on the show. In interviews with multiple "legit" publications, Harrison has even shown himself to be downright funny sometimes.