The House impeachment inquiry into President Donald Trump, which today enters a new phase with public hearings before the Intelligence Committee, is primarily a story about his corrupt abuses of power in seeking to coerce a foreign government to investigate his political opponents. But it also illustrates perhaps the greatest impact yet of the nexus between Fox News, the president, and federal policy.

Over several months this year, the president’s political interests came to dominate U.S. policy toward Ukraine. His personal lawyer Rudy Giuliani spearheaded an extensive disinformation campaign and created a parallel policy track that eventually subsumed the work of federal agencies. Vital military aid to Ukraine and a state visit by its president, Volodymyr Zelensky, were apparently conditioned — perhaps illegally — on Ukraine’s willingness to conduct criminal investigations into Trump’s perceived foes for the benefit of his reelection campaign.

The plot was on the threshold of success. Zelensky was preparing to give a public interview promising to probe former Vice President Joe Biden and alleged Ukrainian involvement in the 2016 election when the aid was abruptly released as a whistleblower’s complaint threatened to expose the scheme. That complaint, which has been repeatedly vindicated by the testimony of firsthand witnesses, and the release of Trump’s July phone call summary with Zelensky in which he asked for the Ukrainian president to “do us a favor” by opening those investigations, led inexorably to today’s hearing.

Fox’s role -- and particularly that of Sean Hannity, the network star who also privately advises the president -- was central to every phase of the story. The network was the source of the president’s long-held animus toward Ukraine, the vector of Giuliani’s disinformation campaign, a common former employer of some key figures and a unifying factor of others, and the fountainhead of arguments that Trump and his House Republican allies have used to try to minimize the scandal.

The Ukraine scandal shows that Fox has been all but running the country. The network’s programming may ultimately bring down Trump’s presidency — or fulfill Roger Ailes’ dream and serve as the bulwark that preserves it.

Fox stoked Trump’s rage toward Ukraine