6. the purpose of an interest group is to influence

It is to influence... Public policy! As well as to educate the general public, as well as policy makers, on their issues. They also look for ways to fund their causes.

- Sincerely, Ouma

The KKK experienced  a resurgence in the 1920s because of its strong ties with the political atmosphere of the 1920s, and its guise of protecting morals and its expanded vigilante justice services beyond the usual Anglo-Saxon Protestantism of blacks, Jews, Catholics and immigrants, etc, to those they now perceived as lawbreakers like illegal gin runners, unfaithful spouses, corrupt public office holders, etc. They also introduced paid "kleagles" which inspired  membership by millions of people.

Explanation:

During the 1920s, KKK experienced a resurgence by blending of their extreme acts with common acts. With this new methods of administration, they were able to get sponsorship and sympathy from the general white populace, and were no longer seen as masked extremists but rather as a community fraternity organisation. To make them look like they were on the side of the law, the KKK got involved with local vigilante services, and prosecuted many bootleggers and corrupt politicians and even perceived cheating wives, inciting what would appear as a form of moral guidance. However, with all these new reforms and methods, their lynching and persecution of minority groups still remained, and a series of feuds within its political circle led to its demise late in the 1920s