The other side of the original argument is this: someone like The Rock has a huge advantage, but on the other hand anyone without a following will be at a huge disadvantage. What happens if a celebrity politician tweets a falsehood like "my opponent supports VileIdeaXYZ" and the opponent has 300 Twitter followers and can't pay to promote a tweet?
I don't think a system that favors people based on how much money they have access to is great, but I also don't think a system that elects people based on their fame is great. Having both paid and unpaid options for reach provides a little bit more balance.
Running an outright dirty campaign would break ToS. So even if they were protected from deletion by virtue of being a politician, their tweets would no longer be included in feeds. It'd be political suicide.
Proper enforcement is hard. They won't get there soon. It'll come slowly for a few years to avoid mistakes. When AIs get reliable at detecting lies/harassment, enforcement will become the norm. (my prediction)
I don't think a system that favors people based on how much money they have access to is great, but I also don't think a system that elects people based on their fame is great. Having both paid and unpaid options for reach provides a little bit more balance.