Krono
Certainly the assassination of Ferdinand is a proximate cause of WWI, but there were much greater forces in play. The great powers had giant mechanized armies for the first time, they had plans for the deployment of millions on very strict deadlines, and they had the belief that failure to meet those deadlines would mean national destruction.
I think it is more plausible to argue that propaganda of the deed helped to end the gilded age and usher in the New Deal era, which was America's golden era.
I also act under political desperation. Only under the most optimistic assumptions will electoralism be able to save us from climate change; currently the most likely outcome is human extinction. If the propaganda of the deed has only a 5% chance of saving us from our modern gilded age and the resultant climate-induced end of civilization, then I say it is a chance we must take for we are running out of serious options.
Democrats have been spoiling every race and letting us slip into fascism, so we might as well try something different, right?