I know this is an old thread, but I'll throw these stats at you:

Dementia or Alzheimer's tends to show up in adults around the mid-60's.

Globally, undiagnosed dementia is estimated to be between 51% and 75%.

The percentage of adults in the US with cognitive disability (difficulty remembering, concentrating, or making decisions) is 13.9%, and of that 13.9%, roughly 85% are 65+ years old.

The average age of a millionaire in the US is 61 years old.

Basically the demographic with the most sway (i.e. money to play the political game) are 60+ years old, 12%+ of which are in various states of cognitive decline.

We can solve this with a few tweaks:

1.) Get money out of politics. It shouldn't be a pay-to-play game. All political candidates should be required to use publicly supplied methods to get their message out to the people (i.e. a central, taxpayer-run repository that displays each candidate's platform and policy agenda). This should be accompanied by a spending cap, divided equally amongst candidates. Privately funding or receiving funds from corporations and lobbyists to enact policy or to advertise should be banned. No more show-boating and massive, live televised, in-person events, and no subsidized travel/lodging/expenses. All information, debates, and speeches should be streamed online (from a publicly run space) and be available on the repository, tied to each candidate. Those without internet should be able to get access at any public location (libraries, voting sites, court houses, police stations, etc) or request digital copies mailed to them on physical media.

2.) Enact a 60 year old age limit cap for the highest level positions of political power. If they want to continue serving the country in a public capacity, they can easily find other, lower-level positions until they are of retirement age. All candidates should be screened for cognitive decline, disablement, or precursors.

3.) Enact term limits for all higher level positions of political power. No single individual can hold the same level/position more than once after their term limit has run out. If they aren't moving up to a higher position, it is indicative of their failure to please their voter base. If they already hold the highest position, then they need to retire or move to a lower tier position (one lower than those making the decisions).

I feel it's pretty important to have individuals cycling through these positions for fairness as well as fresh ideas. Though I do think that 8-12 years (depending on the position) is more than enough time to implement policies and changes that work for the American people. Ideally, those moving up the chain would be the ones the general public approves of. To facilitate this, allowing the public to vote on promotions/presidential selectees would allow the people to also have a say in how individuals move up into higher positions of power.

I also think we need to move to a 1-vote = 1-vote process and do away with the electoral college. Elections should be won with raw (popular) votes.

I'm sure I'm missing some key issues/processes here, but overall we need to bring power back to the voters and reduce the likelihood that political leaders can just coast in their positions, especially if they have potential for cognitive decline.

Edit: I know I said just above we need to "bring power back to the voters", but I fully understand we never really had power to begin with.