Why is Randall Terry running in the Democratic primary?

Terry is running this ad on the local ABC affiliate in Boston now, aiming at the many people in Southern New Hampshire who watch WCVB, Boston. Judging from his list of culture war issues, it appears that his only problem with the current Republican field of candidates is that they are not nearly extreme enough for him.

According to this article, WCVB listeners have flooded the station with complaints asking that the ad be taken down, which of course WCVB cannot do. Federal law requires that political advertising not be censored.

What possessed Terry to claim to be a Democrat? Is it a Republican false flag attack? Does he seriously think he has any chance of winning the Democratic nomination, or is he just seeking publicity for his culture warrior causes?