There should be tests that one has to pass in order to be an elected official. I mean, if a janitor or clerk has to pass a civil service exam, the people who run our country should have to as well
We do. They’re known as elections.
People often just vote for a name the recognize or a name that is associated with their party. Most voters either don't know the extent of Feinstein's mental decline or they straight up don't care because she is a member of their party. People often ignore inconvenient truths.