That’s not really how they use these drones, or how you would use a drone to assassinate someone. For the case of Trump you’d use a FPV drone that weights maybe 750 grams and can lift an extra 400gramms of whatever payload. And then you just kamikaze it into the target. It’s pretty easy and cheap. A drone like that if you build it yourself is maybe 250 bucks on the low end and maybe 400 for a long range drone. These things are fast as fuck and you can be a good km away from the target. If you are even a mediocre pilot it’s pretty hard to miss. I don’t know shit about explosives, and how you would make it go boom, but just flying a 500g drone into someone’s face at 100kmh surely sends a message.