Political means about or concerned with politics:
Ex. Can you think of a political solution to this problem, as opposed to an economic one?
Politic means tactful, in a formal context:
Ex. Can you think of a politic way of telling the Chairman the workforce think he's being stupid about this.
There is one use of politic I can think of where it has the sense of political; when it's used in the expression the body politic, meaning the political establishment.