Re: Err .... aren't you somewhat glossing over...
Remember the fun-and-games with the Swift Boat Veterans a few elections ago?
Yes, and I can see how you could challenge that, though probably not prevent it. However you can't prevent:
"Gangs of drug fueled ferals [sic] Polar Bear hunting in Houston!!!" or "BLM thugs playing the Knockout Game with residents of retirement community!!" or "PizzaGate!!!"
... and that sort of thing is unstoppable without repealing the 1st Amendment and fundamentally re-framing the parameters of freedom of speech.
A better target (IMO) would be to legislate away the "person hood" of corporations. That doesn't require a constitutional amendment and would at a stroke, boot huge quantities of corruption and bribery out of the system - which is, of course, why it won't happen. Turkeys don't vote for Christmas. What they do is deflect attention from the real issues (Koch Brothers, Goldman Sachs) onto scary monsters living under the bed.