As de jure segregation formed and solidified in the south:

De Jure segregation is basically legal racism that is facilitated by laws. This allowed the law enforcement officials to make it legal to not allow black people to use certain restaurants, bathrooms, water fountains, or to sit in only certain sections because of the color of their skin. The south was in favor of slavery and historically very racist, though slavery was illegal, de jure segregation allows increased levels of prejudice and racism to fester and grow.

They made a checks and balance system to equal power within the branches. the "check" meant that one branch would watch one branch and "balance" them if they were too powerful. if you want more info on this, i would just google checks and balance system.