Yeah, even Welker realized Biden had just made a screw up of epic proportions that could very well cost him the election. She opened the door wide and tried to give him an out to save himself by saying he misspoke, but Biden instead doubled down.
There was a story one of the Fox News anchors tweeted about how at the moment that exchange occurred, one of the NBC staffers in the shared press room facepalmed and turned toward one of the other staffers and said, "Well it's going to be a long four years during Trump's second term."
Maybe, but this story was posted here on FR at 8:24 PM Eastern, which would have been 7:24 Central. I don't think the debate had started at that point:
Overheard in debate room from a well-known correspondent from a leading anti-Trump network
That story contained this quote: "It’s going to be a long 2nd term."
In fairness, a lot of liberals were probably thinking this last night.