What is unconstitutional about a president running for a 3rd term?

A president running for a third term is unconstitutional due to the 22nd Amendment, ratified in 1951, which limits individuals to two elected terms in office. This amendment was established to prevent any single individual from holding too much power for an extended period and to promote democratic leadership turnover. Attempting to run for a third term would violate this constitutional provision, making such a candidacy inherently unconstitutional.