When the phrase politically correct was first used, it had a much more literal meaning. During the early 20th century, debates raged between hardline Communists (who adhered rigidly to Stalinist doctrine) and the less dogmatic Socialists. From the Socialists’ perspective, the Communists had defined what was “correct” to believe, politically speaking. Anybody who toed the Communist party line was therefore politically correct.
If right wingers are aware of the historical connection between political correctness and Communism, they aren’t very vocal about it. I’m surprised; I never expect a conservative to pass up an opportunity to conflate a liberal idea with something un-American.
At any rate, the phrase politically correct has evolved dramatically since the 1950’s. When liberals appropriated the phrase near the end of the 20th century, they changed its meaning to something less Orwellian: self-restraint from saying or doing things that would marginalize or discriminate against minority groups, particularly those that are already socially or economically disadvantaged. Almost overnight it became de rigueur to say Native American instead of Indian (unless you happen to be referring to somebody from Mumbai, of course). Gender neutral firefighters and salespeople replaced firemen and saleswomen. And of course it became more appropriate to refer to your black neighbor as African American or, more recently, as a person of color (although the last term can refer to any non-white person). And Morgan Freeman wishes you wouldn’t bring it up at all.
While we’re on the topic… Don’t confuse true political correctness with mock political correctness. Calling a short person vertically challenged doesn’t do anything to avoid discriminating against a minority group (although it is kind of funny).
You can offend people and still be PC; in fact, making a conscious effort to be politically correct will offend just about any conservative. When late December rolls around and winter’s chill is in the air, try saying “Happy holidays” or “Season’s greetings” to an RWCM (rich white Christian male) conservative. I guarantee he’ll get so angry he’ll froth at the mouth. There: you’ve been offensive and inclusive. Everybody wins!