No, they are the biggest problem and as long as they exist they expand other problems. The biggest reason the Senate, Congress, and house aren't working right is that we are so divided and the KKK were the first true signs of a division long ago. They aren't the root cause, but rather the true root is the USA not fighting them in the first place.
Prove is shown in the first years they existed. Grant had a chance to wipe them all out, but it wasn't the government that stopped him, it wasn't congress or senate that stopped him but the mere fact that all the USA people were too "tired" to fight them. The KKK is the last embers of the Civil War, and we refused to put out that ember, the first line of true separation between us and until we are we rid this separation we will never agree on anything, therefore yes, not defeating the KKK is the reason why Congress, Senate, and even the house still isn't working right at all. All other laws, worldly things, rights even are pointless without a unity the choose them.