Why is the minimum age to be U.S. president still fairly high at 35?

Question

According to Presidential eligibility conditions, a President can serve if they are at least 35 years old:

• be a natural-born U.S. citizen of the United States;
• be at least 35 years old;
• be a resident in the United States for at least 14 years

The second condition seems to have been a great trouble for some candidates:

Many youth rights groups view current age of candidacy requirements as unjustified age discrimination.

In 1972, Linda Jenness ran as the SWP presidential candidate, although she was 31 at the time. Since the U.S. Constitution requires that the President and Vice President be at least 35 years old, Jenness was not able to receive ballot access in several states in which she otherwise qualified

Also, quite a few Western / developed states have age requirement as low as 18 years old: Australia, Belgium, Denmark, France.

Why not lower this threshold? It seems that in US it is quite hard to become a young president anyway.

Answer 1

The reason for the founding fathers to do this was in part because they viewed the President as supposed to be an elder statesman who had shown through his career to be reliable in his values and not prone to the changing whims of the public, as well as effectively lead the nation and represent a generally unifying acceptance of a large majority of people over a wide majority of states as the job would largely be the guy who has to represent the nation to the rest of the world.

Of all the age restrictions in the Constitution, it is the oldest with Representatives needing to be 25 years old and Senators needing to be 30 years old. It should also be noted that the youngest person elected to President was Kennedy at age 43, and the youngest President ever was Teddy Roosevelt, who ascended from Vice President, following McKinley's assassination, at age 42. Most Presidents were in their 60s, with Donald Trump (70 at inauguration and 69 at election) edging out Reagan (69 at Inauguration, and when asked during a debate in 1984 if the age of the candidate should be a deciding factor, famously quipped that he "would not exploit for political purposes my opponent's youth and inexperience." His opponent, Walter Mondale, responded by visibly laughing on screen.)

Answer 2

The age minimum is set by the US Constitution. It is very challenging to pass constitutional amendments, and so far not enough people have both wanted to change and cared enough about changing the age minimum for it to be changed via constitutional amendmendment.

Answer 3

Your title question reads as a somewhat more mechanical point than your closing one, but perhaps I’m just mincing words.

Why does US still require the President a fairly high age (35) in order to be able to serve?

Possibly more daunting than the requirements needed to amend the constitution is the incentive to do so in the first place. From a standpoint of their job, members of congress are elected to represent the interests of the people of their state/district. From that perspective, it would be a poor use of the public servants’ resources to pursue a change few of their constituents want or care about. At the risk of stereotyping, as we age it is fairly common to view the inexperience of those younger than us as less suited to leadership than we like to think of our older and wiser selves. So with relatively little concern among the voting-eligible population and over 2/3 of that population being over 35, it seems most of the constituency is unlikely to want their representatives make this happen.

Then consider the composition of congress itself. The vast majority is well over 35. This implies you’d need 2/3 of a collection of people averaging well beyond 35 to vote for it even if it were gaining popularity among voters.

Why not lower this threshold?

I read this as more philosophically pondering whether there is reason for the limit’s existence. hszmv already spoke to the founding fathers’ reasoning. There are plenty of quotes attributed through centuries to famous elders maligning the youth of the day https://proto-knowledge.blogspot.com/2010/11/what-is-wrong-with-young-people-today.html and examples of youth discounting their elders (OK Boomer). Philosophical questions rarely have a single truth. Here’s a barometer. Think back to a 1/3 of your life ago. Do you feel you were better equipped to and likely to make better decisions then or now? There are other factors, but overall experience usually counts for something. Assuming we would like “the leader of the free world” to make good decisions, it’s not the worst limit in the world.

Answer 4

Based on youth rights groups viewing the 35/yr age requirement for president as "unjustified age discrimination" and various western nations having 18 as the age requirement, "Why not lower this threshold?"

While the constitution does specify the age requirement, the age can be amended. Even so, why the age shouldn't be amended comes down to brain development into adulthood. The prefrontal cortex is the last part of the human brain to develop. Research indicates that the prefrontal cortex continues to mature into your 30s and reaches full maturation around 35 years old. The prefrontal cortex (the adult brain) is responsible for using reason rather than emotion to make decisions. Adults in the mid 30s forward are better at sorting, compartmentalizing, and understanding information in the world; therefore having a fully developed prefrontal cortex makes for better decision making, greater understanding, and better leadership skills overall. 18 year old's are often run by their emotions, whereas 35 year old's are run by logic and the ability to manage their emotions in an adult way to ensure decision making isn't purely emotional.