Okay sure. Let's go with and I can take it as you just wanting to waste my time?
Media has it's own issues, yes. However it cannot change video evidence that is out there of candidates, maybe editing and presentation but not the raw footage. I think it is the Americans that ignore the problems.

Okay so this is about Ken not me. And you really believe an election is sufficient evidence to prove that someone is cognitively fit? If they couldn't pass the fitness test to make the ballot in the first place we wouldn't have to deal with their campaign lies to begin with.

Sad truth.

Is it perfect? No. Is there a way to game the system? Probably. Does it need way more thought, regulations, etc? Sure! But maybe something like this could help us from congresspeople having freezing "episodes" on the floor as they talk. I've thought plenty about my country. Thank you. #uspol

If they don't pass no one needs to know they even tried, hell they could even try again if they wanted.

Every time their position is up for re-election, they have to take it again and those results are public record to help us decide when we go to the polls.

It would be administered by qualified medical and psychology professionals for accuracy. For transparency the test could be made public. For their first election if the candidate made it on the ballot, clearly they passed and at that point could publicly release it.

Logistics aside let's just pretend this was possible even if it wasn't shot down by the mentally frail in congress already.
My personal preference would be to have it administered as a prerequisite to get on the ballot, however I'm sure someone somewhere would have a problem with that.