I believe that an EMP is impractical due to the crazy power draw. Non-nuclear EMPs are typically explosively pumped and have a very short range. Jammers (which is what the radio gun is) could work, but are civilian-illegal.
The Russians apparently used electronic warfare (maybe not EMP in particular) very effectively against the Ukrainians. One U.S. officer described the Russians' capabilties as "eye watering".
Off topic, but what are you talking about? Heller, which is when the supreme court first noticed an individual right in the 2nd amendment in over 200 years, was decided in 2008.
Since that is currently the high-water mark in 2nd amendment rights on the pro-side, I assume you can point us to reversals since then, apparently occurring on a daily basis?
Well said drones might not need real time radio communication or they could communicate optically. GPS denied navigation is something missiles have had for a while so jamming GPS is out. The small size also means that less current will be induced.
That being said, it would probably be better to use lasers to burn them out of the sky. It probably doesn't take much energy to damage their wings.
Given all the sensor capable drones, it would be interesting to see a project with hovering drones that could react to being shot at effectively, but I gues their reaction times would be much slower than The velocity of the shot.
[1] http://www.gizmag.com/anti-uav-defense-system-radio-beam-dro...