Ability to selectively enable or disable people from being able to access voters is tantamount to having a huge influence on election results.
While in the past you could avoid using social media, today this is THE way to reach most of voters. Most people no longer pay substantial attention to what happens on television, forgot what radio is (it is a little bit of noise your car gives so that it is not quiet) and don't read printed papers.
Now, this time it happened for Trump and we can discuss whether this was or was not a good decision, but the question is who is going to wield the power like that in the future and whether it is even permissible do to something like that.
On one side you have the idea of free speech, but then added to social media you have inevitable disinformation as anybody can get amplified and amount of information is such that it is not possible to verify and vet it.
In the past you would have handful of news-generating organizations and it was easy to spot and call false information. But this is forever gone, there seems to be a need to find out some kind of new equilibrium that will allow detect and filter misinformation without anybody having power to singlehandedly "vanish" people from public life.