New York (CNN) New York Times chief television critic James Poniewozik asserts that Donald Trump's evolution as a "TV character" was a critical aspect of his ascent to the presidency.

In his new book, "Audience of One: Donald Trump, Television and the Fracturing of America," Poniewozik also examines Trump's TV obsession and how it has affected his time in the White House.

"He in very many ways used television to become president, but then TV kind of became the president, because what he was seeing on TV set his agenda and controlled his mood and determined the world that the rest of us would live in," Poniewozik told Brian Stelter on this week's "Reliable Sources" podcast.

There were, of course, many factors that helped Trump win the 2016 election. But Poniewozik's book describes how the power of television was a pivotal factor. It wasn't always the case "that you could go pretty much directly from hosting a reality game show in primetime on NBC to becoming the most powerful person in the world," he said. That happened in 2016 "because of TV. It happened through TV."

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