Gerrymandering is the process by which congressional districts are redistributed between the states based on changes in population

Gerrymandering is the process where congressional districts are redrawn in a way to keep one party in power. They are often very oddly shaped. Cities and towns can be a part of 3-4 districts. By cutting up a district that was strongly one party you can add more members of the party that is already in power. Both political parties are guilty or redrawing lines to help themselves stay in power. 

United states v.  nixon, 418  u.s.  683 (1974),  was  a landmark  united states supreme court case  that resulted in a unanimous  decision  against president richard  nixon, ordering him to deliver tape recordings  and  other subpoenaed materials to a  federal  district  court.