The Civil Rights Act of 1964 prohibits discrimination on the basis of race, color, religion, sex or national origin. Provisions of this civil rights act forbade discrimination on the basis of sex, as well as, race in hiring, promoting, and firing.
This is a system set up by the founding fathers, people would want to stick with the passed down, original tradition.
It also gives low-population states a say in federal government where higher population states might overwhelm them, if its possible to that is. Plus, in my opinion at least, popular vote is pretty much useless
Increased fear of Communism, the US became an even more capitalist society.
The amendment grants suffrage to former male African-American slaves, but not to women.