1520s, "science of government," from politic (adj.), modeled on Aristotle's ta politika "affairs of state," the name of his book on governing and governments, which was in English mid-15c. as "Polettiques." Also see -ics.
Politicks is the science of good sense, applied to public affairs, and, as those are forever changing, what is wisdom to-day would be folly and perhaps, ruin to-morrow. Politicks is not a science so properly as a business. It cannot have fixed principles, from which a wise man would never swerve, unless the inconstancy of men's view of interest and the capriciousness of the tempers could be fixed. [Fisher Ames (1758-1808)]
Meaning "a person's political allegiances or opinions" is from 1769.