It works by having you sign a shareholder's agreement (at the point of investment) where you commit to voting in a certain way for certain key issues, including the structure of the board. Investment is usually not only a contract between the investor and the company, but also a contract between the (new) shareholders. You would be required to support "their representative" to be on the board, no matter how many percent of shares and votes you and they had; and then the board has the rights to govern the corporation according to the corporate bylaws.
Ask Rogers, the board just tried to fire the CEO, the CEO just tried to fire the board, but those elections happen at a different time, and the CEO need the trustee of the family shares to agree.