I hesitate to make generalizations about TSA security and hiking poles, but I have brought hiking poles, collapsed and in a duffel bag, through security in Chicago, Las Vegas, Dallas, San Francisco, Seattle, Washington, DC,and a few other places I can´t think of off the top of my head.
I was afraid about getting them through security in Valencia, but I think that if they are collapsed and in a duffel bag they don´t trip any security alarm. It may be different if you are carrying them. I always bring them in a duffel so that if I have a problem getting them through as carry-on, I can quickly check them as checked baggage and hope that they arrive.
But as I said earlier, I know that the Santiago airport is different, so when I go home, I always check them in the duffel that I send up to Santiago from the local post office when I start my camino.