The back cover of the copy of the "Second Treatise" that I read describes John Locke as an "early Enlightenment philosopher". While Locke wrote in many ways like the popular image of an Enlightenment thinker, he carried with him earlier medieval ideas. For example, while he rejected monarchy and the Divine Right to Rule he maintained the belief in a natural order for the world as well as a reverence for God and the Bible as authoritative. He encouraged citizens to revolt against their leaders if they were being treated unfairly and he believed in the Natural Law (the moral law that is written on the hearts of all humanity regardless of race or culture). In other words he walked a middle path between medieval "conservatism" and Enlightenment "liberalism". Politics is one of my weak points both in interest and comprehension, but Locke's lack of conservative/liberal extremity made him strike me as quite a sensible person. It also helped that Locke often drew on Biblical examples to prove his points. Add a little religion and the politics pill goes down easier for me.
Locke's treatises greatly influenced the founding fathers of America and it isn't hard to see why. Locke's writing is full of the "American dream" of democracy: everyone is born free and equal, citizen's right to revolt against a corrupt government, the government should do what is best for the people, citizens should have a voice in government etc.
When thing that struck me when I was reading Locke was how different his approach to government was to Machiavelli's. While Locke wrote about how government ought to be, Machiavelli wrote about how government actually is. Machiavelli is the political realist and Locke is the political idealist. Where Machiavelli says that a prince must be exempt from conventional morality if he is to be successful, Locke asserts that leaders owe subjection to the laws of God and Nature just like anyone else.