Partisan Gerrymandering
gerrymandering
the practice of manipulating legislative district lines with the intent of influencing
election outcomes to benefit one group/party over another.

How is it done?

Figure A
Hypothetical State with 50-50 split of Democrats and Republicans
Figure B
How a Republican-dominated redistricting process might draw the map
 Concentration of Population Partisan distribution in districts
 LowHigh   1  2  3  4 
Democrats Democrats42%38%40%80%
Republicans Republicans58%62%60%20%