Even the US constitution was/is no guarantee against such - no document/law will ever be.
But really, business can be (and in some cases probably is) the driving force behind political corruption.
By the same token, political corruption can be (and in some cases probably is) the driving force behind abuses by businesses.
Personally, I wish there were a way to separate money and power, at least for the countries leaders.
The two are far too closely linked for me to fully trust any politician.