The public has been able to be swayed by media for a very long time. The CIA in particular has been deeply involved in it [0]. For some reason this was deemed okay, or at the very least acceptable, by the public. The only difference between the CIA controlled media cited and social media is the lack of US government control.
I do appreciate the irony here. That every other election was so-called "free and fair" yet an absolute wildcard gets in for 2016 and the deepest level of coping by every agency in the union was witnessed. I am not a fan of Trump, but if elections are truly "free and fair" then 2016 was legitimate. If 2016 wasn't legitimate, then why would anyone have any reason to believe 2020 was legitimate? I'm not intending to start a conspiracy theory fight here - but rather raise the question that is trying to be asked. If "foreign actors" elected a president in 2016, then whose to say they didn't in 2020? Or 2008? Or 2004? Who can you believe? I'd argue you couldn't believe any agency who might have an interest in having you believe otherwise. Maybe our elections are actually selections and in 2016 the powers that be lost the information war.
[0] https://en.wikipedia.org/wiki/CIA_influence_on_public_opinio...