Over the course of his life, President Trump has used a few particular data points to evaluate his success.

The first is stock indexes, which he has long used to measure his financial success. When he starred on NBC’s “The Apprentice” 16 years ago, he focused intensely on tracking television ratings. When he announced his candidacy for the Republican presidential nomination in 2015, he began tracking poll numbers.

All of these numbers are still integral to Trump’s sense of self and used by Trump to measure how his presidency is coming along. That’s not a contestable claim; he regularly talks and tweets about how each is faring. He’ll tweet that the Dow Jones industrial average has hit 25,000 (again) or that whatever poll from whatever pollster is good or bad depending on how well it suggests he’s doing.

He even still tweets about television ratings, oddly enough. Trump now uses Fox News ratings the way he uses the indexes, as an external proxy for how well he’s doing. If Fox beats CNN, Trump seems to think, that’s a measure of the extent to which he himself is crushing his opponents.

Fox beat CNN in the most recent ratings, and Trump noticed.

That little aside — “(thank you President Trump!)” — is the president’s heavy-handed attempt to try to strong-arm the network into wringing out any even modestly critical coverage of his administration. What’s more important, though, is the bigger throughline. Trump claims that Fox’s rivals are “fake news," a term he uses to describe critical coverage, and implies that they are failing specifically because of that lack of generosity in their reporting.

To Trump, this is a sign that his side is winning. But that’s not what these ratings show.

Consider new polling from Suffolk University, conducted for USA Today. Suffolk includes a question asking respondents which TV news or commentary source they trust the most. Among Democrats, responses are split broadly, with no single network or source earning being identified by more than a quarter of the partisan group.

Among Republicans, more than half identify Fox News. An additional quarter-plus say they don’t trust any source.

One result of this is that Fox News ends up with a bigger audience than CNN or PBS and NPR (combined as an option in Suffolk’s question). If we roughly overlap Suffolk’s responses with the distribution of the population by party (using Gallup’s latest numbers), you can see that the density of Republican confidence in Fox News makes it the most trusted single source.

This is an approximation of how the cable news battle works, and Fox’s audience is a bit less homogeneous than that approximation suggests. But it makes clear one thing that the ratings contest reflects: Fox News is the go-to network for most Republicans, while Democrats divvy up their viewership more broadly. And that helps power Fox News to ratings victories.

That Suffolk asks people about their viewership preferences allows us to reinforce how strongly cable-news preferences overlap with partisan ones.

Take the head-to-head question about the 2020 presidential contest. Overall, former vice president Joe Biden leads Trump by double digits in the poll. That’s a function of broad Democratic support for Biden and broad Republican support for Trump. Independents also prefer Biden by a hefty margin.

But compare views of the contest as seen through the lens of trust in TV news and commentary sources. Those who say they trust CNN or PBS the most have views of the race that roughly mirror the Democratic view. Those who trust Fox look like Republicans.

That holds across the questions Suffolk asked. Democrats and those who trust CNN the most think Biden is likely to win. Those who watch Fox and Republicans think Trump will win.

On approval, the same pattern.

One pattern that emerges as we look at these questions is that those who say they trust Fox News the most seem to be a bit more aligned with Republicans than those who trust CNN or PBS are with the Democrats. Across the questions shown in this article, the average gap between the views of those who trust PBS the most and the views of Democrats was about 10 points. The difference between CNN viewers and Democrats was about six points. The average gap between those who trust Fox News the most and Republicans was about three points.

That includes three questions Suffolk asked about the personal characteristics of the candidates. Biden has distinct advantages on views of honesty and his ability to unite the country; the two are viewed generally evenly on the question of having a vision for the country.

This correlation between Trump’s support and the audience that views Fox News as the most trustworthy source of news is neither new nor surprising. But, again, the lesson one should take from Fox’s success isn’t that there’s a massive-if-quiet universe of support for Trump that is muted in the popular conversation. It’s that Republicans heavily turn to one network that regularly bolsters Trump’s presidency. It’s that the breadth of support shown by members of one party to one network helps that network succeed in the ratings wars against multiple opponents that split non-Trump viewership.

Those ratings don’t show a quiet reservoir of pro-Trump sentiment. Like the Suffolk poll itself, it shows the boundaries of Trump’s obvious and visible base.