We’ve created a shadowy “pre-crime” area. This question was inevitable to come up sooner or later.
We should be asking if America should be operating in this manner. If the person is too dangerous to fly, put him in a rubber room, because he’d also probably bomb a bus, a train, whatever.
However, the due process overhead would be immense; a lot simpler to keep lists.
If our intelligence agencies weren’t tainted — even overridden — by liberal politics, we wouldn’t even be having this discussion.