Your slip is showing
Here's an odd sentence from AP:
The directive did not do anything to prevent attacks from homegrown extremists who were already in America, a primary concern of federal law enforcement officials.
It's buried in an article about Trump's immigration actions.
This kind of sentence almost never makes sense. There are an infinite number of things not done by every definite action that does do something. You always need to write about what is happening, not the infinite number of things not on the table. Trying to fold something in creates an argument, and a heavy burden, to show that the thing not done is so intimately related to thing done as to justify our attention.
What does "homegrown" have to do with immigration? Nothing, of course. It might be much more or much less important, but it's a different topic. If you want to explore how the two concepts could be related, there are several choices--violence, of course, but then why not write "The directive did not do anything to prevent date rape" or any other violent act. This sort of reaching isn't appropriate for a news story; it's appropriate for a study of framing issues, maybe, but not a news story.
There is some possibility that the sentence refers to all the odd little "lone wolf" attacks that Obama was more likely to describe as work place violence, though they all had this strange, though consistent and predictable, tendency to have some relation to Islamic extremism outside the country--being converted or some such. Not likely, though. AP has been on the side working hard to convey that Islamic extremism is less important, not the side working to convey that it's more important. Even if this is the intended reference for the sentence, it's still a different issue (not to mention, if this is the intended meaning, then it's an argument that Obama should have done what Trump did many years earlier, so as to reduce the influence and contacts from these sources of influence that are converting the homegrown Islamic terrorists).
Of course what's really at stake is the politics. AP, like Obama and many others, still believes the Tea Party is a threat, but Islamic terrorists are just a coexist issue. All this sentence is really saying is, "Why are you making me write this story, instead of a story about the REAL threat to America, including Trump, the Tea Party and Republicans, in that order."
(Another sign of inherent weakness: How does AP know it's a concern of federal law enforcement officials, much less a "primary" one? It might or might not be, but there is no quote or work to support it. Again, it's just a sign of a reporter straining to convey what he isn't quite willing to say directly: YOU PEOPLE ARE IDIOTS! WHY DID YOU ELECT TRUMP!)