Trump delivering a speech earlier this year. (Clip from video)

Overnight, news broke of a campaign shake-up at Trump Tower. Campaign director Paul Manafort, who had jockeyed past Donald Trump's original campaign manager to take the reins of the effort, was himself being pushed aside, replaced by Steve Bannon, executive chairman of the hard-right and fervently pro-Trump Breitbart News. (He'll step down from that role temporarily.) Bannon will act as the chief executive of the campaign, and Kellyanne Conway, who worked for a pro-Ted Cruz super PAC in the primaries, will serve as campaign manager.

The Bannon-Conway news came less than 24 hours after a report from the New York Times that another fixture in conservative media was aiding Trump: Roger Ailes, ousted from his position at the top of Fox News after reports of numerous instances of sexual harassment of women at the company. Trump's campaign denied the Ailes report, which was later confirmed by other sources, including CNN. Meaning, then, that Trump's campaign is being explicitly run by the guy behind Breitbart and quietly aided by the guy behind Fox News.

Why the change? Our Robert Costa reports that Trump has been annoyed at having been told to alter his tone and strategy for the general election campaign and that he tapped Bannon and Conway with the goal of "letting me be me."

This is a pretty stunning move with just over 80 days until the election, all else aside. But it also reinforces the problem at the core of Trump's candidacy: He still doesn't understand the difference between the primary electorate and the general.

Donald Trump won the Republican primaries because he was himself. He made a wide-ranging case against business as usual, lacing his rhetoric with faulty statistics and personal inconsistencies — but it worked. He didn't get a majority of support from Republican voters (more voted against him over the course of the primaries than for him), but he built a core base big enough and early enough that he weathered a primary season that was much closer than he now likes to admit. That base has stuck with him.

But it hasn't really expanded. Trump has been mired in the low-40s in national polls for months. What we've seen since Trump solidified the nomination in May and June is that his base of support has become more solid — while other groups have moved further away.

Gallup found that — for the first time since it started asking people — Trump's convention made voters less likely to support his candidacy. Some groups strengthened their support for him, as our Greg Sargent determined: White men and whites without college degrees supported him more after the convention than before. Women and nonwhites? Nope. That pattern was reinforced by subsequent polling.

(Philip Bump / The Washington Post)

What Trump needs to do over the next 12 weeks is to figure out how he expands that base beyond the white men without college degrees. Bannon and Ailes in particular seem like weird picks to make that happen.

A national poll in July found that 83 percent of Fox News viewers already back Trump. Fox News, like Trump's convention, has helped solidify his existing base. It's pretty safe to assume that the much-smaller audience at Breitbart, fed a steady diet of pro-Trump stories, is also already on board. Trump's campaign, in other words, has been a natural extension of the media work that Bannon and Ailes have been doing. The themes around which Trump has centered his campaign are within the Fox News universe (though closer to the edge); they are squarely within the Breitbart space.

To what extent, then, can they offer insight into appealing to voters outside of that audience? What evidence is there that their efforts won't have the same effect as that convention, galvanizing an already galvanized base of support? Can Roger Ailes make programming that appeals to black women in North Carolina?

But let's take Trump at face value. He believes that he won the primaries by virtue of being himself — which is true — and he has been flummoxed at the fact that the same strategy hasn't worked in the general. As I wrote over the weekend, this isn't a mystery: The audiences in the primaries and in the general are vastly different. The lesson Trump has taken from the past few weeks of bad polling, though, isn't that being himself isn't working — it's that he isn't being himself enough, as though he had significantly changed his approach of late, which he hasn't.

Trump views the presidential election as though it is a ratings battle for "The Apprentice." Voters are viewers, and it's media publicity that drives viewership. This inclination is revealed in his conflation of crowd size and social media activity with poll support; it's revealed in his ongoing frustration with the news media as being an obstacle to his success. The media's coverage of Trump hasn't really changed much over the past year and a half, but polls now measure Trump's support against the full electorate and not just primary voters, so he's doing worse.

Imagine if "The Apprentice" was getting killer numbers with viewers 65 and over, but then the advertisers wanted to buy spots on shows that appealed more to millennials. To turn things around, Trump loops in two of the guys that are the best at getting people aged 65 and over to tune in.

Trump is now and always has been running a media campaign, and the new move makes that explicit. It's not a bad strategy, and it worked for the primaries. But it's been a failure in the general so far, and it's very hard to see how pushing harder on the idea will make things better.

Costa tweeted that "Bannon has convinced Trump that rest of campaign needs to be bare-knuckles brawl." If "The Apprentice" started having fistfights every night, people would tune in — or they might just stop watching television altogether. At this point, Clinton voters giving up on the campaign might be as good as Trump can get.