Government's definition comes from the people.
The people are swayed by whatever is topical and prevalent at the time.
Terrorist groups are terrorist groups by what they DO.
Hate groups, generally speaking, are hate groups by what they SAY. (Yeah, I know, some hate groups do take action, but then it's criminal)
That difference can't be highlighted enough, in my view.
You may not like what a hate group says, but that's a case for free speech, not for being treated like a terrorist group that actually DID something.