I have to say, I'm a member of some "tiny" groups. Growing chapters in 20 states does not fit the definition of "tiny".
From the story linked above:
Today's KKK doesn't have to rally in public places. Instead, they can hide on the Internet and secretly spreading their hate message to a whole new generation and a bigger audience.
They are doing that by getting to a larger audience using streaming video, advertising white power rallies and concerts, even broadcasting a new Klan newscast.
The anti racist group's research found states with growing Klan chapters not just in the south but in Michigan, Ohio, Maryland, Pennsylvania and New Jersey.
But regardless, the real message is that Klan members, sympathizers and like-minded organizations and individuals could be anywhere. You don't know what the guy in the cubicle down the hall is doing on his off hours...