A new Trump campaign ad painting Biden as senile is at the top of YouTube's homepage and getting lots of play on Fox News during the Democrats' convention

• The Trump campaign's latest effort to counterprogram the Democratic National Convention uses the prime real estate of the top banner on YouTube's homepage and is getting lots of play on Fox News.
• The video juxtaposes clips of Joe Biden from the Obama administration with instances of the presumptive Democratic nominee stuttering or losing his train of thought.
• While the Trump campaign trying to paint Biden as unfit for office or in "cognitive decline" is nothing new, the ad marks the most intense iteration of the line of attack so far in 2020.
• Biden has been open about stuttering while growing up and has described himself as a "gaffe machine."

The Trump campaign is shifting its "cognitive decline" line of attack against Joe Biden into high gear, buying coveted space atop YouTube's homepage with a new ad that's also getting plenty of play on Fox News.

The nearly two-minute video juxtaposes clips of Biden from the Obama administration with instances of the presumptive Democratic presidential nominee stuttering or losing his train of thought on the 2020 campaign trail.

Biden, 77, who's described himself as a "gaffe machine," has also been open about stuttering while growing up.

The Trump campaign has been trying to paint Biden as unfit for office for quite some time — a task complicated by President Donald Trump's obsession with a dementia-screening test he took — but the YouTube placement and the ad's appearance in Fox News segments on Tuesday demonstrated a more concerted push.

Counterprogramming big moments for his Democratic foes — like this week's Democratic National Convention — has become a staple of Trump's campaign and presidency.

By early Tuesday afternoon, the YouTube video — which was published on Saturday — had racked up more than 1.7 million views. The clip even made its way onto MSNBC, where the "Meet the Press" host Chuck Todd used it to lead into a segment on the Trump campaign trying to settle on a message to defeat Biden.

A Biden campaign spokesman hit back at the Trump campaign's ad on Tuesday by quoting the president describing his cognitive test: "Person. Woman. Man. Camera. TV."

Other non-campaign sources, such as the popular "Joe Rogan Experience" podcast, have also scrutinized Biden's mental acuity. A video of Rogan raising questions about Biden's fitness for office has 2.8 million views, and the prominent podcast host has said he won't vote for Biden because he believes the candidate has early-onset dementia.

Biden has bristled at the notion of taking a cognitive test and said he's not worried about Trump's attacks.

"I can hardly wait to compare my cognitive capability to the cognitive capability of the man I'm running against," Biden said at a news conference earlier this month.