Interesting way of counting they got there.
In New York alone The nazis are counted three times as are the klan.

The Nation of Islam (they're the "Radical Right?"

) is also counted three times as is that other bastion of Radical Rightness, the National Black Foot Soldier Network

. They even count the radical Catholics three times.
Then they count the nazi womens auxillary as a separate group, their hate literature publishers as a separate group. their trust fund providers as a separate group.
Do you see a pattern here?
The Southern Poverty Law Center, bless their little liberal hearts, mongers fear for their funding in much the same way that the NRA does. The more dire the threat the more they collect in donations.