I'm not an expert on history, but I don't think that holds true, at least based on my limited knowledge. As I understand it, we've always had a government partially beholden to certain large interests, but it's offset by having to maintain some level of restraint on behalf the public interest.
If we look back at our government's founding, we have large interest groups pushing to maintain horrible things such as slavery. But eventually we moved past that.
I won't claim that things couldn't be better; we certainly have a lot of room for improvement. But I don't think we're doing as poorly as many people would like to believe.