I think you're using too many SAT words, and not enough sentence structuring.
I believe the responder is saying "the 2016 election was less 'pernicious' to democracy than the 2020 election." But to be honest, it's impossible for me to tell which election you think had which results from this sentence.
EDIT: Please note that working within the constraints of the system will always be less pernicious to the system than working outside of the constraints of the system.