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Katie Couric

What's behind the meteoric rise of Megyn Kelly

What's behind the meteoric rise of Megyn Kelly

How did Megyn Kelly get so big so fast?

That's the question I've been asking since news broke Tuesday of the 46-year-old anchorwoman walking away from Fox News and a reported four-year $100 million contract to join NBC.

On the eve of the launch of "The Kelly File" in October 2013, I predicted success for her new show — then wondered if I had sounded too effusive. She was the new kid on the prime-time cable TV block, and some analysts were wondering whether she could hold the lead-in audience Bill O'Reilly delivered in the 8 o'clock hour on Fox. Not me.

But just a little over three years later, here she is in a league by herself as a TV news personality. There...