“any of us who opposes what the government does could be labeled as such.”
Not just the government. The Democrat party as well. The SPLC is a major resource used by the government to determine “right wing terrorists”, and it is appalling what organizations they list.
Dr. Ben Carson (who they later removed from their list), for his “anti-LGBT views”.
The Family Research Council. (Being listed resulted in their being violently attacked.)
Those opposed to unrestricted immigration.
Those opposed to further Muslim immigration.
Those who believe in single gender restrooms.
Those who support the police against those who attack them.