A footnote attached to the report by the Homeland Security Office of Intelligence and Analysis defines "rightwing extremism in the United States" as including not just racist or hate groups, but also groups that reject federal authority in favor of state or local authority.
"It may include groups and individuals that are dedicated to a single-issue, such as opposition to abortion or immigration," the warning says.
... That's right, when they say 'extremism' they are not talking about what we think of when we think of 'extremists' -- they are actually talking about mainstream conservatives who actually oppose things like (gulp) abortion.
(Of course, this comes just in time for the Tea Parties ...)