I think you are wrong Urmstongran - I think he has gone downhill quite quickly.
If you listened to his great "State of the Union" address I don't think your suggestion that they have been covering up for him for ages is true.
He dealt with hecklers in a witty but firm way, he was all the things you want in a statesman and worked the room afterwards. Some of this after-chat was caught on mike and you can hear his comments and responses. He seemed pretty switched on then.
And it was long and he showed no signs of weakness then.
Also, it was an evening, which, if he was in bad shape then that would have caused more problems. It's well known that people with dementia have problems in the evening - and that's believed to be why Trump doesn't do so well at night. According to numerous psychologists they think Trump has progressive deterioration in memory, thinking, ability to use language, behavior, and both gross and fine motor skills.
Until recently psychologists said they believed Biden was showing signs of aging - but not dementia.
Are you irritating in RL? (light hearted)
Recalled for a further appointment after a routine mammogram


) there will be a reaction, Trump has an appeal to people as did Johnson, he saw what was happening and used it. And then everyone looks confused when it happens again and again and again.