To be fair they can just blat out the entire band you might operate in and saturate the receiver so that it couldn't actually decode anything. Automating evasive action would struggle to take into account the fact that the jammer can move to track them. The drone could try to return to base but it would lack GPS so it would have to do that via the IMU.
But don't worry, these devices are illegal for anyone but federal agencies to use and they'd need to apply for a licence to use them from the FCC. If you're flying a drone and the federal government don't like it then you probably are going to have their finger in uncomfortable places very soon anyway.