system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why is the US president elected to a 4 year term, but members of the senate get unlimited 6 year terms?
gpt
It is worth pointing out that the 2-4-6 year term system (House of Representatives, President, Senators) was put in place to prevent what the Founding Fathers feared most: tyranny.  On any given election cycle, only 1/3 of the Senate is up for re-election so that one botched/rigged election cannot completely take over the Senate.

Rotating congress(wo)men and presidents in and out in different intervals assured relatively smooth transitions of power and guarded against radical change in direction of the country.

Presidential term limit is a new thing.  Basically: politicians got scared when FDR was elected to four consecutive terms.