Why do you think that in the last 50 years people of more diverse backgrounds have chosen to run for the presidency? What historical events or changes in American society might explain this?

People want to represent their gender, racial background, There Background and want to make clear equal rights to all. This motivates voters of there diverse backgrounds to vote for this person.  

Explanation:

"Lawless: We’re seeing an uptick in terms of high level professionals working in presidential politics among the Democrats as well. Something that I would note that makes racial diversity a little bit different than gender diversity is that women aren’t monolithically Democratic. So, when it comes to racial diversity, almost every African-American, almost every Latino in elected office today, is a Democrat. And so, when you have a lot of Democratic candidates run, that really opens the door for a lot of African-American and Latino voters to get enthusiastic, and also for operatives to get jobs."

"a government in which power is divided between state and national levels". federalism is a system of government in which entities such and state and province, share power with the national government.