President Trump’s reelection campaign in a new ad is attacking presumptive Democratic presidential nominee Joe Biden’s mental acuity, a frequent target of the president’s.

The ad, timed to coincide with the virtual Democratic National Convention, contrasts footage of Biden speaking in 2015 and 2016 with clips of him seemingly losing his train of thought in 2020.

"Did something happen to Joe Biden?" reads the opening text of the ad, which then juxtaposes Biden in 2015 saying in a speech that “he went and became president, I didn’t go and I’m still vice president” and Biden in 2020 stuttering and repeating “in addition to that” in an interview.

“You know there’s a, during World War II, uh, you know, Roosevelt came up with a thing that, uh, you know, was totally different than a, than the, he called it a, you know...” Biden says in a later clip from a 2020 interview.

Trump himself has repeatedly suggested Biden is in cognitive decline and touted his own performance on a neurological test in contrast. However, some within the Trump campaign were reportedly hesitant to incorporate the attack into campaign messaging, according to Axios. Several campaign advisers reportedly warned the line of attack could offend senior citizens, a demographic with which most polling shows Biden in the lead.

Ultimately, however, those in favor of the attack won out. "We think it's very important that voters fully assess Joe Biden's qualifications and fitness to be president," a senior campaign official told Axios. “Our data show that people are concerned about his ability to do the job.” The official declined to provide the data in question to Axios.

"Donald Trump is spectacularly failing every conceivable strategic test by ramping up mentions of this subject at all," Biden campaign spokesman Andrew Bates said in response to the ad.

"Joe Biden sounded the alarm about the [coronavirus] outbreak early, whereas Donald Trump is still promising us the virus will magically 'disappear.' Joe Biden has highlighted the advice of medical experts throughout the pandemic, but Donald Trump publicly encouraged COVID-19 victims to inject themselves with disinfectant. Trump has even said that we should nuke hurricanes out over the water. And if that's not enough for you, 'Person. Woman. Man. Camera. TV.' ” he added.

A July Monmouth University poll indicated more Americans, 52 percent, believe Biden is mentally and physically up to the job of president, compared to 45 percent who said the same for Trump. The same poll, however, indicated stronger confidence in Trump’s stamina among his supporters than among Biden’s. Seventy-two percent of Republicans said they are very confident about Trump’s stamina, compared to 47 percent of Democrats who said the same about Biden.

Updated Tuesday at 9:54 a.m.