Tell that to the Supreme Court. Which has said that, because of free speech, corporations are allowed to spend as much money as they wish directly advertising for political causes.
Yeah, and they're wrong. That's why one of the main features of the campaign is a Constitutional amendment. People tend to forget that the Supreme Court isn't the Supreme Law of the Land -- they only interpret it.
They may be wrong, but with the way common law works, a lot of judges are obliged to judge in accord with their reasoning.
As for the phrase "only interpret it", the way the law is interpreted bears so little relation to what is written that there is no "only" about it. For the most obviously extreme example, consider how radically the interpretation of the phrase To regulate Commerce with foreign Nations, and among the several States, and with the Indian Tribes changed in the 1930s.
If you're unfamiliar with that history, the short version is that Congress went from being able to regulate direct trade crossing state boundaries to being able to regulate anything that relates to commerce, even indirectly. For instance the Civil Rights Act is legal because of the Commerce Clause. I like the outcome, but do not agree with the reasoning used to get there.
The Supreme Court is fundamentally just a bunch of people wearing robes. Just because they think money is the same as speech does not mean it really is, or rather, that it should be treated as such. Also, they are humans, and can be bought or threatened behind the scenes.
Tell that to the Supreme Court. Which has said that, because of free speech, corporations are allowed to spend as much money as they wish directly advertising for political causes.