That one?
But when a corporation expresses false advertisements, they are fined -- regardless of their "freedom of speech."
A private citizen should be able to lobby. Corporations should not.
The problem is that they exist at all. Nothing in the Constitution says that the government (of Delaware, no less) should have the legitimate power to wave a magic wand and create fictitious legal entities that are effectively immortal but are born without a moral compass.
If it did have that legitimate power, then it's still bad that it can happen for the payment of a $250 fee and filing of a stack of legal paperwork.
Everything that the whiny lefties gripe about with capitalism is actually the fault of corporations, not capitalism. Sounds like you're ok with them existing though, you just think that's possible with them a "little less powerful" or something.
Perhaps start off with removing the corporate veil. Officers of corporations (or any incorporated entity) are now personally liable for what goes on. This could pave the way for trimming down extra-national entities like multinational corps (the risk is immense for there to be bodies buried in various dark corners of huge corporations -- only the insane would take on these positions).
If you want to know if I'm a card-carrying communist or not, feel free to read this: https://news.ycombinator.com/item?id=36132733
It's couched in mild language, because of the venue we're in.
Why would you ever work towards it as a long term goal? Once your faction had even a little political power, you'd have more control over corporations. And they're quite powerful in their way. They'd become too appealing at that point.
Much more fun to tame the godzilla monster and sic it on your enemies.