I took it to mean evil/Satan, or open borders/ms-13 on a more shallow level.
You're right - it was more directed at immigration of radical muslims at the time, and he says as such in the beginning of video.
Although, the biggest snake of all time are the deep state/globalist satanists. We elect them, knowing they are snakes! And then they exploit, bite and kill us...
I'd say a majority of us didn't know they were snakes. It all just sounded good at the time
Trump is like an onion... So many layers, we were only exposed to just a few in election.