the actual quote is,
"It may include groups and individuals that are dedicated to a single issue, such as opposition to abortion or immigration "
I understand that English is a notoriously difficult language to learn, NEP, so I'll try to help you. Consider it a gift.
1. The statement is that said extremism "may include..." The word "may," in English, denotes that it also "may not" include such individuals and groups.
1b. However, in the case of the brutal murder of the doctor who provided abortions, we have proof positive that this terrorist threat did
include an individual who was motivated by a single issue, opposition to abortion.
2. "May", therefore, is unnecessarily soft. It does
include such murderers who are dedicated to single issues.
2a. You need only worry if you are planning to commit murders, or have done so already, in the name of your cause.
3. The word "include" in this context is very important in English. Even though right wing extremist terrorists, like the murderer of the doctor a couple weeks ago, and the murderer of the guard at the Holocaust museum, include
such individuals or groups, they are not identical
to said individuals and groups. There is an overlap.
3a. For example, the Nazi at the Holocaust museum was motivated by blind extreme right wing ideology and racism, combined with hatred of government and with a dash of gun-owner paranoia mixed in. The murderer of the doctor, by contrast, was a single-issue murderer, from what I hear.
4. Most importantly for your purposes, this also does not mean that every idiot spewing "abortion is murder" empty rhetoric is a murderer or capable of it. Although radical and nonsensical, the heightened rhetoric of the anti-choice crowd does not in and of itself constitute a propensity for such actions.
It is undeniable that the rhetoric of the anti-choice contingent often would lead a reasonable man, if he truly consumed the rhetoric as if it were true, to become a killer himself.
For example, I have no trouble telling you that if it were 1943 and I was in a room in Nazi Germany with Mengele and a scalpel, if I got the drop on him, there would be no more Mengele. No further provocation needed. That is the proper response to Mengele in that setting. Were he in America, I am sad to tell you, I would let justice take its course, since here he would be held to some sort of account. But I certainly would kill Mengele if the local law were on his side.
Now then: I think the Holocaust happened, and that it was mass murder, and that killing would have been justified to stop it.
I know that abortion is a medical procedure that a lot of people oppose. Usually they say things like "Abortion is a Holocaust," and then dance around why they do not, therefore, kill doctors.
They usually say things like "taking a life is never right."
Really? Not for Mengele in Nazi Germany? I think killing Mengele would have been right, and so do these hypocrites.
The fact is, the majority of them
do not believe their rhetoric either, or else are simply gigantic pu$$ies.
So yes, there is a direct line from that rhetoric to the actions of the misguided murderer who killed Dr. Tiller. The rhetoric's hypocritical and idiotic, but you're safe: even hypocritical and idiotic speech is protected.
Murder, however, is not.