Presumptive democratic presidential nominee Joe Biden gave another one of his rambling, incoherent speeches yesterday. This one was so bad, the sign language interpreter seemingly couldn’t keep up.

In a speech in Wilmington, Delaware, the former vice president recounted what he cast as President Donald Trump’s missteps, from Trump’s early dismissals of the virus to his more recent refusals to wear a mask in public appearances. His speech —marked with long pauses, confusion, and hyperbole— was so disastrous, even the sign language interpreter appeared to give up.

Biden indicated he was trying to “simplify” things for the audience. President Trump shared a hilarious clip of the speech, set to “Curb Your Enthusiasm” background music. You can watch the video below:

Clearly, it was anything but “simple.” In the midst of the ramble-fest and dead air, Biden’s sign language interpreter, who appeared visibly befuddled by what she heard, seemed to surrender. Her eyes nervously darted off to the side as if she was looking at someone off camera.

Also during yesterday’s speech, Biden hurled another “lying dog face” insult, this time directed at a Fox News reporter who later questioned him about his cognitive abilities. As the press conference drew to a close, the reporter, who had already asked two questions, said, “One last question, real quick.” A grinning Biden interrupted him, saying, “you’re a lying dog face…” before letting him continue.

The reporter then said, “I’m 65, I don’t have the word recollection that I used to have, I forget my train of thought from time to time, you’ve got 12 years on me, sir—have you been tested for some degree of cognitive decline?” Biden responded by saying he is “constantly tested.” He said, “All you gotta do is watch me and I can hardly wait to compare my cognitive capability to the cognitive capability of the man I’m running against.” Oh, we’re watching, Joe. The entire world is watching…

The former vice president drew criticism earlier this year after he called 21-year-old college student Madison Moore “a lying dog-faced pony soldier” after she asked about his poor performance in Iowa during a rally in Hampton, New Hampshire. When the woman said she had never been to a caucus, Biden replied, “No you haven’t. You’re a lying dog-faced pony soldier.”

Moore later spoke out on the incident, calling the moment “humiliating” and said Biden attempted to “invalidate me by exposing my inexperience.” Biden’s camp later said the line was taken from a scene in a John Wayne movie, where a Native American chief refers to Wayne as a “lying, dog-faced pony soldier.”

The former vice president’s mental acuity and age has become the subject of media scrutiny and a target for President Trump and his campaign who have pushed the narrative that Biden is the candidate who is addled. Since launching his White House bid last April, 77-year-old Biden has made a series of public gaffes, often stumbling over his speech or forgetting facts during campaign events or interviews. There appears cause for concern.