I wonder if it’s simply a matter of contrast.
Just a few weeks ago it was Trump compared with Biden, and the latter was looking every bit of his 81 years, with his speech and mannerisms diminished far beyond 2020 when he was more in the spotlight of a national election. Next to that, Trump almost seemed spry, and the national focus and rhetoric was more on the aging Biden.
Now we have Harris and Walz, who are running all over the country with an image of youth, vibrancy, and joy, coming at Trump and Vance with all the wit and bravado. Now, by comparison Trump looks like the feeble geriatric who everybody at the dinner table wishes would stop with the senseless jabbering.
I know there’s more to it than that, but I really think the change is not so much Trump himself and his antics, but his opponent who with contrast is pointing out how incompetent and deficient as a person Trump is. If it was still Biden as the nominee, Trump could still be lisping the same fucked up rants, but everybody would still be talking about how Biden’s age has made him unfit for office.