Historically, over 80% of House Representatives are reelected, and noncompetitive districts may be a major factor in this. Congressional districts being divided in such a way that there is reduced competition within a given district is harmful to our representative democracy.
The current system for determining congressional districts is flawed, and has the potential to lock down districts as red or blue for decades at a time, regardless of the true desires of the voter base.
Further investigation of the effects of gerrymandering on proper competition and accurate representation is necessary to insure a congress that properly reflects the will of the American people.
sources: http://www.fas.org/sgp/crs/misc/R42831.pdf
http://www.opensecrets.org/bigpicture/reelect.php