Great presidents get big things done by recognizing that continuous work with Congress is perhaps their foremost duty and best use of their time. It is a central element of their job description; notwithstanding that it is often part of their job that they least like doing. Other presidents like LBJ, Ronald Reagan and Bill Clinton understood that the tedious and often unpleasant work of engaging with Congress is the only way to lead this country forward. After all, the Founding Fathers created a system where the Congress and the Executive were co-equal branches of government. If President Obama follows the Lincoln model, he can truly be a great and historic president, and can change the course of history in economic policy, immigration, education and the other big issues of our time.