A "special interest" is one I do not share. One I do share is "the public good".
Labor is a special interest; breaks for manufacturers like me are the public good. We create wealth - at least for ourselves.
By Lela
Special Interest
Some autistic people have a very strong and passionate interest in something that can last for several years, known as a Special Interest or SPIN for short.
A special interest group is a large caucus of really excited people. They are always trying to get everybody all worked up over some specific issue. Sometimes they vote for candidates that they all like at the same time.