The 432678th Democratic presidential candidate debate in Los Angeles wound up on Thursday night with a final question from the moderators — something vague and vaguely festive about forgiveness and gifts.

However, when it was former vice president and current frontrunner Joe Biden's turn to answer, his anecdote about a young person with a stutter he met on the campaign trail got caught on a sound. "I-I-I-I-I-I can't talk," said Biden, as if quoting them.

While a few Twitter users initially thought Biden had attempted an ill-advised, ableist imitation of a person with a speech impediment, many more quickly shared a profile of Biden from The Atlantic, published in November. In it, he spoke at length about his lifelong struggle with a stutter of his own, which still seems to affect the fluency of his speech. (He's also spoken about it before, relating it back to the film The King's Speech in 2011, discussing it with NPR in 2008, and working with nonprofits focused on stuttering.)

Oh hey, speaking of ill-advised, ableist imitations of a person with a speech impediment:

I I I I I I I I I I I I I I I hhhave absolutely no idea what Biden is talking about. #DemDebate — Sarah Huckabee Sanders (@SarahHuckabee) December 20, 2019

Former White House press secretary and civility enthusiast Sarah Huckabee Sanders mocked the stutter in a now-deleted tweet, saying "I I I I I I I I I I I I I I I hhhave [sic] absolutely no idea what Biden is talking about" — and was promptly ratio'd to absolute heck for it. Before deletion, the tweet had just over a thousand RTs and nearly 15,000 replies, almost all furious.

Christian is the first word in your bio. Would you say it's Christ-like to make fun of a person with a stutter? — David Gardner (@byDavidGardner) December 20, 2019

Yes, you have proven that you’re factually challenged. It’s from all that time you spent lying and gaslighting Americans at the White House. — Alexandra Chalupa (@AlexandraChalup) December 20, 2019

It's called empathy. Maybe you can find an actual Christian and ask them to explain it to you. — Kevin M. Kruse (@KevinMKruse) December 20, 2019

Cool to know that, as a moderate stutterer (Biden would be a low severity stutterer compared to me), I’d have zero shot at mounting any political run bc I’d be made fun of. That’s neat. 👍🏼 — Ho Ho Quid Pro Quo 🦌 (@justinpbolinger) December 20, 2019

remember when you were mad for like three weeks that someone talked about your eye shadow — Rob (@robrousseau) December 20, 2019

Sanders "clarified" her post in a second tweet, which was then also deleted within the hour: "To be clear was not trying to make fun of anyone with a speech impediment. Simply pointing out I can’t follow much of anything Biden is talking about."

To be clear was not trying to make fun of anyone with a speech impediment. Simply pointing out I can’t follow much of anything Biden is talking about. https://t.co/6rAf0MwgKL — Sarah Huckabee Sanders (@SarahHuckabee) December 20, 2019

Biden, who got heated more than once during the debate, quote-tweeted the original insult, calling Sanders out with a bonus 'Think of the children': "I’ve worked my whole life to overcome a stutter. And it’s my great honor to mentor kids who have experienced the same. It’s called empathy. Look it up."

I’ve worked my whole life to overcome a stutter. And it’s my great honor to mentor kids who have experienced the same. It’s called empathy. Look it up. https://t.co/0kd0UJr9Rs — Joe Biden (@JoeBiden) December 20, 2019

Uncharacteristically, Sanders then backed off and apologised.

I actually didn’t know that about you and that is commendable. I apologize and should have made my point respectfully. https://t.co/fbmVAqDoWI — Sarah Huckabee Sanders (@SarahHuckabee) December 20, 2019

While she may have been unaware of Biden's stutter, it's not the first time a former or current figure in the Trump administration has made fun of a disability.