While I am focusing in on the anti-abortion issue, this could well have parallels elsewhere.
Hypothetical (and not so hypothetical) possibilities, of statements from anti-abortionists:
We need to kill the people who are killing children.
In the literal reading, this could be advocating capitol punishment for murders. It should be protected free speech.
The context, however, or even the literal statement, could turn this into:
We need to kill the doctors who supply abortions.
This might be interpretable as meaning "Supplying abortions should be a capitol offense". But the obvious meaning, to me, would be to be advocating murder. It probably should still be protected free speech.
BUT, if the statement actually provokes someone to go out an murder a doctor, then the maker of the statement could and should be prosecutable as being an accessory to murder. This situation may well blend into a "gray area", which could go as far as the following.
Here is a list of names and home addresses of doctors who provide abortions (said list follows).
Remember - This is being said in an anti-abortion context. I think this could and should be prosecutable, even if no doctor is harmed as a result. It would still be an action that would be endangering the life of someone.
The bottom line: It may be your right to say most anything. But if you do, and it can be legally connected up to being part of the commission of a crime, you better be ready to pay the price.
Moose