When Confucius spoke about the chaos in China taking place during the fall of the Zhou dynasty, he reasoned the flaw in the political system to be an improper use of relational terms. Vassal lords would liberally describe themselves as kings, metaphorically usurping the position as true head of the dynasty and thus King of China. This was important because over time, underlings in the imperial hierarchy would forget their upward allegiance and conceive selfish conflicts against other lords and damage the solvency of Zhou rule. To Confucius, the most important element of a stable political society was that all people understood their obligations and rights and their titles and what they implied. A political culture in which kings forgot they were kings and subjects forgot they were subjects is just as disastrous as a family where the parents forget who the parents are and children forget who they are as well.
I'd like to draw a parallel between the discourse of early Confucianism and the political discourse of today. It's no so much that senators have forgotten that they are senators and justices have forgotten that they are justices, altho that does seem to happen on occasion, but the terminology used to describe various "schools" of political though have muddled themselves to such a degree that no longer are ideologonyms used in a idiosyncratic and predictable manner. Some words have nearly lost all vestiges of anything but a perceived insult: a television commentator may call a guest a "fascist" in the same way he calls him a "pinhead." The celebrities in political culture have no habit of using words correctly, opposing ideologies may as well be just invectives. This damages amateur political orators, that is, pretty much everyone, in that it poorly equips them with the idea that there are no such things as solid political perspectives and words can be used in any way they please. I think this is especially bad in the United States, where due to heavy pop-politics and entertainment news channels, people take holistic views on politics; they let their stereotypical ideologies seep into every aspect of their lives and try to personalize politics in a way that contravenes the technical terminology used in political science and economic journals.
So instead of an essay format here, I have decided to simply list some terms which are oft abused in manners that are incorrect and really only make the speaker look abundantly stupid in ways he or she cannot imagine.
Liberal- The term liberal has now become somewhat of the adjectival form of Democrat. In the scholarly community and in every other nation in the world, Liberalism is an ideology that holds personal freedom as an upmost good and traditionally would contrast at its time of origin with Monarchists and more restrictive forms of republic. Most people relevant in the politics of the western word are liberals. Both of the primary political parties in the United States are liberal; if anything, the Republican party is more-so due to its lofty respect of free markets and "hands-off" government. Also keep in mind that prominent liberal thinkers of the past include Adam Smith and J.S. Mill.
Conservative- Conservative is a more general term used in and out of politics meaning conventional or old-fashioned. A conservative is simply someone who is skeptical of political change, so in a sense it is more correctly used in the United States than liberal. Just keep in mind that liberal and conservative are by no means antonyms. Also note that for example in post-Soviet Russia, the conservatives are communists; the word isn't so much tied to an ideology as a composure of criticism of the novel.
Progressive- Democratic politicians realized somewhere along the line that liberal had grown negative connotations and began to call themselves progressive. It is a generally more accurate word for them, and is mostly an antonym for conservative. Progressive had been used previously in American political life denoting the Republican Party under Theodore Roosevelt. Progressive policies back then included regulatory reform and trust busting, however progressive, like conservative is more of a general term describing an attitude to change and the goal of politics.
Communist-Socialist-Marxist- a more difficult one because people will have their own snob definitions of these, especially self-proclaimed communists, and even more so anti-communists. Firstly, Marxism is not so much as political term but a social one; a Marxist is someone who holds that "[t]he history of all hitherto existing society is the history of class struggles," as quoth in the Manifesto. It is an outlook that sees political society as a long-term battle between the poor and rich, the opprest and powerful, or the stigmatized and privileged. It follows Hegelian thought in thinking of historical developments in a thesis-antithesis pattern, ebbing and flowing between the few powerful and many powerless.
Socialism and communism are political incarnations of this. Originally the two were synonymous about until the influence of the Russia Revolution when socialism was rebranded as a transformatory state between the oppressive capitalism and the ideal communist non-state. Socialism thence has taken on a life of its own describing mixt economies and, in the United States, any functional form of government; obviously this is a little too far. I myself use communism and socialism in the traditional way, oft without a distinction between the two, but err on using socialism more because it is less stigmatized; communism evokes ideas about oppressive Soviet Europe which obviously do not necessarily align well with Marxist ideals, even if one acknowledges corruption to be inherent in tentative communist states.
Also keep in mind that real communists, as in not angsty pseudo-rebellious teen "communists," do not hold communism as the polar opposite of capitalism; capitalism to them is a part of a long string of social development which has indeed come a long way improving life since tribal and feudal societies. Indeed Marx praises capitalist society (we cannot know how genuinely) for its productive capabilities and the necessity of its engines of production in the future socialist ideal.
Capitalist- Firstly, a capitalist is someone who owns capital; it is not someone who "believes in capitalism" or something like that. Secondly capitalism is a Marxist exonym, a term originally used by Marxists to describe presocialist society. It makes little sense to call yourself a capitalist considering the term was coined to make the argument that the present society was unjust due to a disequality of capital ownership. I suppose it's similar in its lack of thought to when people call themselves atheists, thus defining themselves by what they're not. Either way, I refrain from using this term unless writing on something with a specifically Marxist theme because that is the only place this term belongs. People with "I ♥ Capitalism" bumper stickers are missing the point in using a word of semi-vituperation in an adoring sense.
Neoconservative- the way people use the prefix neo- might lead one to think it was Greek for "despicably evil." Few people given the label of neoconservative would actually call themselves this due to the heavy stigmatization which is smelt now by all sides of the political spectrum. Still the word has a fairly precise meaning; a neoconservative is a post-Cold War typically American political theorist with the stance that, not only is the American political system of liberalism and democracy is superior to all others, but it should be spread, forcibly if necessary, for the goodness of all people. Regime change is the name of the game, and under the Bush administration, neoconservatives oft stood at the helm.
Of course the term neoconservative is just that, a descriptor of foreign policy. One may thing that it is tied to the heftily religious social policies or a face turned from regulatory capture (see below), but none of this is the core of neoconservative thought (that said, with a interventionist foreign policy at the highest pedestal, anywhere is fair game for the politics of staying in office).
Corporatism- The one is probably the absolute worse; I have never seen this used correctly by anyone who doesn't have a PhD, I have no idea why. There seems to be the pernicious idea that corporatism has something to do with corporations, which of course is hilariously inaccurate. It again exposes the idea that you can take a word, take -ism on it, sound smart, and make an argument without thinking about it.
Corporatism is a general idea that society should be composed of organized bodies (corpora). It's similar to a guild system in which people of one trade or calling, farmers, clergy, merchants, divide into groups and work together in their specialization. The metaphor of corporatism can be used on society as a whole to present an organism of multiple parts, even Paul of Tarsus describes the church as "the Body of Christ" (Corpus Christi) which gave rise to the use of the term in is way today.
Typically when people say "corporatism" they mean to say "regulatory capture," but I suppose that lacks the emotionalism needed by most people juggling the concept. I once visited the Talk: corporatism page of Wikipedia and saw an indignant poster who, burdened with the popular misuse of the term deemed the page to be "revisionist" because it did not mention the "obvious" fact that corporatism is "corporate control" instead it talkt about thinkers actually involved in the true definition of corporatist thought.