A funny thing happened to Trump’s strategy of relying on free media to overcome Hillary Clinton’s tremendous financial advantage. As the campaign has progressed, he has retreated to the one news network that really doesn’t help him reach new voters.

As Michael Calderone noted in The Huffington Post:

On July 31, Trump spoke with ABC’s George Stephanopoulos for an interview on This Week, during which he publicly questioned whether the Gold Star mother of a Muslim army officer had been forced into silence because of her religion. Since that attack on the Khan family, Trump hasn’t appeared on the network. Nor has he appeared on any others except Fox News and Fox Business (save for a phone interview with CNBC on Aug. 11).

Trump ensconcing himself in the Fox cocoon makes perfect sense: He doesn’t want to field tough questions from media outlets that aren’t so intimately affiliated with the Republican Party. But the safety of Fox comes at a price: The viewers of the network skew heavily towards those who are already inclined to vote for Trump. At a time when he needs to win over new voters, he’s decided to preach to the faithful.