Gerrymandering is the act of dividing a territorial unit into election districts to give one political party an electoral majority in a large number of districts while concentrating the voting strength of the opposition in as few districts as possible.
Imagine you are a Republican congressman in the House of Representatives whose district only consists of three people. Now imagine that your party redraws your district so that your three constituents are your best friend Tim, your brother, and your roommate. These are three Republicans whose ideals generally align with yours. Tim’s ideals are almost identical to yours and he will almost always support you. However, there is some risk that your brother and your roommate could be swayed by another candidate, given the right circumstances. So, your party redraws your district so that it consists of Tim, your uncle (who is also a Republican), and someone who holds the exact same views as Tim. Now you feel pretty secure with this set up. You are almost guaranteed to hold your seat since the two Tims are dyed in the wool supporters and your uncle is more conservative than your brother. However, your party finds itself in control of redistricting again and thinks: “hey, we can do one better.” So, they redraw your district so that it consists of three exact copies of Tim. Things are pretty great for you now. You have a constituency that loves you and agrees with you; your seat in congress is rock solid. But, a problem arises.
Your party decides to push a bill that Tim does not support. With the newest redistricting you are only supported by Tim and people who hold his same viewpoints. In short, you are entirely supported by Tims. If you go against what they want, they will throw you out of office and replace you with someone who will. In the past, upsetting Tim would not have been an issue as you could have turned to your brother or your roommate for support. Unless all three of them had opposed your party’s agenda, which is unlikely since they are all members of that party, you could manage to support the Republican leadership and hold your seat. Unfortunately, you are no longer a representative for the Republican party, you are a representative for the Tim party. Either you do what Tim likes, or you start updating your resume.
This reality might not bother you, personally, all that much. You and Tim have very similar interests, so you generally get to vote how you want. However, you pose an enormous problem for the Republican leadership because you have become invulnerable to compromise. You won’t accept half-measures because Tim will oust you if you don’t perfectly represent his interests. On the flip side, neither the Republicans nor the Democrats can run a successful campaign against you so long as you have Tim’s support. This deadly combination eliminates any possibility of compromising with you. Your vote becomes a fact, not a bargaining chip. Either the powers that be do what you (by extension Tim) want, or they accept your vote as lost.
The 30-some House Republicans who have been generally credited with enabling the government shutdown predominantly come from districts that are securely dominated by an ideologically homogenous constituency (Tim). Ironically, the only way to overcome these representatives is by breaking up their constituents through redistricting. The Republican Party is suffering the effects of this the most right now but the Democrats, particularly in Maryland, are trying hard to catch the same disease. The reality is that national parties cannot rely on endless redistricting in order to shore up their power bases. The end result of such a policy will be the ultimate failure of the parties as they lose the ability to control their members through compromise and deal brokering. It may well be the case that the Republican Party would be much stronger if more of its members were elected by fewer Republicans.