1520s, "science and art of government," from politic (n.) "the political state of a country or government (early 15c.), from Old French politique and Medieval Latin politica; see politic (adj.). The plural form probably was modeled on Aristotle's ta politika "affairs of state" (plural), the name of his book on governing and governments, which was in English mid-15c. as (The Book of) Polettiques or Polytykys. 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), "British Alliance," in the Boston Repertory, November 1806]
The sense of "political actions or practice" is from 1640s. Meaning "political allegiances or opinions of a person or party" is from 1769.
1784, "abstract political science; purely speculative treatment of politics, unrelated to practical matters;" see meta- "transcending, overarching, dealing with the most fundamental matters of" + politics. Based on metaphysics. Related: Metapolitical, which is attested from 1670s in the sense of "outside the realm of politics."
1580s, "person skilled in politics;" see politics + -ian. Especially "one engaged in party politics, especially as a trade; one who promotes the interests of a political party," and thus it quickly took on overtones, not typically good ones: "one concerned with public affairs for the sake of profit or of a clique." Johnson defines it as "A man of artifice; one of deep contrivance."
The notion of enlightened, disinterested, and high-minded service to the state goes with statesman (Century Dictionary notes that "A man, however, would not properly be called a statesman unless he were also of eminent ability in public affairs"). For "student of political science," by way of distinction, politicist (1869) has been used.
c. 1600, "sameness, oneness, state of being the same," from French identité (14c.), from Medieval Latin identitatem (nominative identitas) "sameness," ultimately from Latin idem (neuter) "the same" (see idem). [For discussion of Latin formation, see entry in OED.] Earlier form of the word in English was idemptitie (1560s), from Medieval Latin idemptitas. Term identity crisis first recorded 1954. Identity theft attested from 1995. Identity politics is attested by 1987.
"[I]dentity politics" [is] a phrase with notably wide currency in gay and lesbian communities. In common usage, the term identity politics refers to the tendency to base one's politics on a sense of personal identity—as gay, as Jewish, as Black, as female ..... [Diana Fuss, "Essentially Speaking," 1989]