Meanwhile, also from Vox, here's what President Trump is doing during the debates:

Thanks to a massive YouTube ad buy, the Trump campaign’s counterprogramming for the Democratic debate is probably going to reach more people on the site than the debate itself — though it probably won’t persuade many of them.

President Donald Trump’s reelection campaign has bought YouTube’s “masthead” — basically, the advertisement at the top of YouTube’s homepage — for Wednesday, the first night of the Democratic debates. That means anyone who goes to YouTube’s website is going to be hit with pro-Trump messaging. It’s an expensive move, and an effective one.

“It’s one of the highest impact digital ad placements possible,” Daniel Scarvalone, senior director of research and data at Democratic communications and strategy firm Bully Pulpit Interactive, said in an email.

He estimated it cost the campaign between $500,000 and $1 million and will reach more than twice as many Americans as the debate will, if not more. “We’ve seen it reach about 80 million Americans in a single day for buys we’ve done in the past,” he said. (For comparison, the first Republican primary debate in the 2016 cycle got a record 24 million viewers, and that’s because people were tuning in to see the then-novel Trump spectacle. The audience for the Democratic debates is expected to be smaller.)

This morning, there were two boxes atop the YouTube homepage with Trump ads. One is a video of Trump saying that his campaign is delivering him an updated list of supporters at 9 pm Wednesday — the time the debate starts. Both ads point to a text-to-join phone number; those who follow it will presumably start getting text messages from the campaign.

The content is changing as the day goes on. In the afternoon, an ad about immigration, aimed at firing up the president’s own supporters, appeared. YouTube said in an email that the masthead ads are sold on a first come, first serve basis and accepted as long as they comply with its policies.

It’s a somewhat unusual strategy for the Trump campaign, which in 2016 and again in 2020 has largely focused on hyper-targeted ads. The YouTube masthead goes to everyone, regardless of their location, demographic information, or political leanings.

“I’m slightly surprised by it, to be honest, because the average person isn’t a Trump voter or wouldn’t be swayed into being a Trump voter, and if you’re buying out the masthead, that is an untargeted ad buy, and most of their advertising has been highly targeted,” said Ian Schafer, a former ad executive and current CEO of events company Kindred.

Homepage ads, while still far-reaching, aren’t as effective as they once were because most people access websites through direct links to the content they’re seeking — as in, a specific YouTube video.

But the Trump campaign’s move makes a statement: that it has a lot of money and it’s looking to make a splash with it.

This ad buy is just one part of Trump’s Democratic debate strategy

It’s no secret that Trump wants to provide some counterprogramming to the Democratic debates, the first round of which will take place on Wednesday and Thursday. (You can see Vox’s complete coverage and a rundown here.)

Politico outlined the president’s debate strategy, which includes dispatching pro-Trump surrogates for media appearances in swing states and clipping and spreading videos of the debate to highlight mistakes or contradictions.

The president himself is headed to Japan on Wednesday for the G-20 summit and will be tuning in from the air. Last week, he told Fox News’ Sean Hannity that he wasn’t initially planning on live-tweeting the debate, but he might wind up doing it. “Instead of fake news, I’ll make them correct news. And that’s okay,” he said.

In an interview on Fox Business Network on Wednesday morning with journalist Maria Bartiromo, Trump said the debate “seems very boring,” but he’s going to watch “because I have to.” He said the Democratic candidates are a “very unexciting group of people” but it’s “part of my life.”

That’s one way to understand the YouTube masthead purchase — it’s about amping up the attention to his own campaign compared to the Democrats and turning the story, in part, back to himself.

“Trump’s PR strategy is reach, and his ad strategy has been targeting. This feels more like the PR strategy than the ad strategy, but they’ve clearly raised a lot of money to spend on advertising, and I guess this is some shock and awe with that,” Schafer said.