He recalled her pun sessions with advisers that would put her in stitches. "I'm not saying every time you see or hear the laugh it's the appropriate moment," he said. "It's not like someone just told a joke. But I'm saying that's where it comes from."
At times, like when she walks onto a stage after a lengthy introduction, Harris laughs unprompted in the way that politicians often do to try to demonstrate humility — as if to suggest that, while she may be a history-making vice president, she also sees the attention around her as a bit much.
Or she'll laugh amid an earnest policy discussion, seemingly trying to bring the subject down to earth. At a speech in Michigan this month, Harris talked about people waiting months to get their COVID-19 vaccines. "It's July!" she said with a guffaw. "It's time!"
But the laugh that's proved the most polarizing is one that some observers argue is not a laugh at all. It's her reaction, often seemingly inappropriate in the moment, when Harris is asked a question she doesn't like. She laughs, and it's hard to tell if she is doing so to deflect or to signal she thinks the query is dumb, or both.
As state attorney general in California, for example, she drew media attention for a deflective chuckle in 2014 when she dodged a question about whether she favored pot legalization. She replied only with a laugh and a few words that basically restated the question.
She got far more attention recently for laughing defensively and awkwardly when she was pressed repeatedly last month by NBC News anchor Lester Holt on why, as President Joe Biden's envoy on migration from Central America, she had not yet visited the U.S.-Mexico border.
"And I haven't been to Europe," she said, laughing before adding peevishly: "I don't understand the point that you're making. I'm not discounting the importance of the border." (She has since visited there.)
That laugh made it onto news sites, social media posts and cable channels across the political spectrum. Conservative media went into overdrive over Harris' "cackle" or "giggle," mentioning it at least 151 times on Fox Business Network, Fox News, Newsmax and One America News Network in the six weeks since the Holt interview, according to Media Matters, a left-leaning group that monitors conservative media. Fox twice aired a montage that consisted of Harris laughing.
"She doesn't know how to communicate. She just offers that awful giggle that just makes people cringe," former Rep. Jason Chaffetz, R-Utah, said on Fox Business Network.
Alice Stewart, a Republican consultant who has worked on several presidential campaigns, complained, "It's the obvious attempt to evade a question. And she often gets away with it."