Sequence of Junk Identification

I have a political organization spamming me. It's virtually impossible to get such organizations to stop. They just change domains and move on. They are so infuriating that I don't even want to see them in my Junk folder, I want them to go directly to Trash. I set up a filter to do that. When I receive email from <political.org> it should go to Trash. But I'm still seeing it in my Junk folder. If I run the filter '''''on''''' the Junk folder, then it does what I ask, and moves it to Trash. But I want it to do that as soon as the email is downloaded. In the settings for the filter, "Apply filter when Getting New Mail: Filter Before Junk Classification" is checked, so I would think it would work that way, but it's not. The only thing I can think of us that perhaps my email provider (yahoo.com) is marking it as Spam/Junk before it lands in my inbox. Does anyone have thoughts on what I might look at? Are there headers I can look at that indicate what app/service has marked something as Spam/Junk? Thanks.