What’s Gerrymandering… gerry who?

So following the U.S. census, each state redraws their electoral district boundaries i.e. redistricting. The resulting map affects, among other things, the state's members of the House of Representatives. 

But WTF is gerrymandering? So it’s basically manipulating the boundaries of a district to favor one political party or weaken another.

Imagine these are the people in a district:

 
RESIDENTS.jpg
 

Now there is a way to divide the district so that it has a true and fair representation in Congress. You can divide the map like this:

 
1 copy.png
 

This way is compact but unfair because all the reps are democrat. Like this which is neither compact nor fair because you end up with three republicans and two democrats:

 
2 copy.png
 

This way however has a perfect representation: three democrats and two republicans.

 
3 copy.png
 

Voilà!