The Missing 16th Amendment
Years ago someone told me that there had been an Amendment passed just before the civil war, But because of the civil war, the southern states' ratifications were thrown out and the amendment was ruled invalid. I was told that this amendment made it illegal for any lawyer to run for elected office, saying it was a conflict because lawyers are part of the Judicial arm of the Government and should not be running the Legislative or Executive Branches.

I have hunted for some time and have not found any evidence of the such an amendment.  But it would be a good one.

Nonrepresentative. Individuals elected to office in a representative democracy tend not to be demographically representative of their constituency. They tend to be wealthier, more educated, more male, and closer to the majority race, ethnic group and religion than a random sample would produce. They also tend to be concentrated in certain professions, such as lawyers. Elections by district may reduce, but not eliminate, those tendencies, in a segregated society. Direct democracy would be inherently representative, assuming universal suffrage (where everyone can vote).