We have separation of church and state, so why don't we have separation of corporation and state?

Special favors and contracts to certain companies and private contractors, billions in bailouts to the largest banks and lenders, loans and bailouts to "too big to fail companies," the Federal Reserve which consists of private banks that make private profits from controlling the US money supply, special laws/treaties/agreements that favor corporations (NAFTA, eminent domain, China as the most favored nation, low import tariffs for Chinese products, government subsidized incentives to outsource, etc.)--when will there be a separation of corporation and state?