The Sherman Anti-trust Act of 1890 is the big one, but it requires a Justice Department willing to use it.
The FED also had the power to back the Bank of the United States to keep it from failing, but it didn't. And, then we ended up with runs on banks at the Great Depression. So, what good is giving government power when it never uses it when or in the way that it should?
We can have the best laws there could be, but government also has to execute. The record seems to indicate that's a big part of the problem. So, it doesn't matter if we've got the law right. That's just the beginning. And, the end seems to always be big companies with more power and politicians getting their share of the pie.
The main thing is to not just throw up our hands and say, "Oh well, big business is just going to continue to do what they're doing so we might as well just go along with it." Instead, we need to be aware of which candidates, which bills in congress, are going to make it worse and which will make it better. Then, we do what people have been doing for centuries: get up in the politicians' faces and let them know we support them if they do right or will work to defeat them if they do wrong. If a bunch of half-bright crackers with teabags stapled to their meshback caps can scare the shit out of the Republican Party, my guess is that the rest of us can also bring a little pressure to bear.
I'm not throwing up my hands and giving up. I'm just taking an honest look at the history of government regulation. The record is full of examples of government gaining more regulatory power and big business benefiting disproportionately. I honestly am not aware of any situation where that hasn't been the case.
But, we still have a quasi-religious fervor when it comes to praying for the government to protect us. Never mind that corporations are a creation of government. Never mind that the industries we complain about and have the most problems with are the most regulated. Never mind that government involvement always ends up being the tool of the corporations instead of the little guys.
And, I'd love to think that politicians could be kept in check, but the facts don't seem to bear that out. Over 90% of incumbents are reelected to congress. And, people for the most part are too apathetic to pay attention enough to make good choices. Other than the occasional temper tantrum, voters only care about the appearance of something happening.
Government doesn't get held accountable.