Economist blogger E.G. wonders why Democrats/liberals are more apologetic and defensive about their beliefs than conservatives:
In broad strokes, Republicans, especially of the tea-party stripe, are typically proud, at least unapologetic, and sometimes belligerent about their beliefs. Democrats, in contrast, seem to adopt the defensive position by default...To me, the phenomenon in question seems very real, and the explanation seems rather obvious. I'm not sure why E.G. didn't think of it.
Why are Democrats more anemic? One thought comes from the liberal journalist Thomas Frank. Writing in Harper's, Mr Frank argues that while Republicans respond to their base, Democrats have a misbegotten faith in a "Magic Middle" of centrist ideas that are tolerable, at least, to most Americans:A couple of other theories: Democrats are constrained by their insecurities, a holdover from being made fun of by George W Bush and Fox News. Democrats are undermined by deeper, historical anxieties; with the Republicans having co-opted the rhetoric of being the "real America", Democrats feel that they have to explain themselves before they can proceed. Or, there's something cultural going on: there are temperamental traits that draw a person to the Democratic or Republican parties, and those same traits, aggregated, are manifested by the parties themselves.
Democrats, for their part, tend to do the opposite, dreaming of bipartisanship and states neither red nor blue and of some reasonably-arrived-at consensus future in which the culture wars cease and everyone plays nicely forevermore under the smiling, benificent sun of free trade and the knowledge industries.
Conservatives are less apologetic about their beliefs because conservative beliefs have a stronger base of support. Whereas 40% of Americans identify as conservatives, only 20% identify as liberals, with the rest identifying as moderates. These numbers have been very stable over the past two decades. That means that if you are a Republican, hoping to win in a Republican primary, you are appealing to a much more ideological median voter than your Democratic counterpart. And in the general election, trumpeting conservative beliefs will probably alienate fewer of those moderates than trumpeting liberal ones. Case closed.
The more interesting question, and the one E.G. should really be asking, is: why are more Americans conservative in the first place? Since people tend to define their ideology relative to the national average, you'd expect a symmetric distribution of ideology; instead, we have a rightward skewed distribution, with a "long tail" of right-wing conservatives and a short fat tail of liberal-leaning moderates.
My guess as to the reason for the skew is: tribalism. Politics is generally an exercise in coalition-building between tribal blocs who vote for their "team". The "team" can be determined in many ways - race, language, religion, region, or socioeconomic class - and people can identify more strongly or less strongly with any given team. Teams can also overlap. It is these divided loyalties, and the shifting and changing of the coalitions, that make politics so complex.
Who are the "teams" in America? Well, the Republicans are composed of the "white" team (not whites, but rather, people who think of whiteness as their key characteristic), the "Christian" team (again, not all Christians), the "Southern" team, and the "business class". The first three of these overlap a great deal, and those three are very strong affiliations with lots of members. Democrats, on the other hand, are a hodgepodge of disparate little groups and blocs - blacks, gays, union workers, Hispanics, intellectuals, Asians, Jews, schoolteachers, etc. While some of these factions are very strongly unified (blacks most of all), the interests of the various Democratic support groups diverge wildly.
Hence, while the Republican Party is basically a simple deal - deregulate the economy and lower taxes, in exchange for excluding and disenfranchising nonwhites and non-Christians - the Democratic Party has to strike a much more careful (and much more changeable) balance. This accounts for the "defensive" and apologetic tone that E.G. wondered about. The fact is, Democrats' hopes for victory rest on their ability to convince everyone-who's-not-a-Republican that together they form some sort of political "center", while Republicans' hopes for victory rest on their higher voter turnout and on the fragility of the Dems' coalition.
(Note that this entire dynamic can be understood by watching the movie "Revenge of the Nerds". The white jock fraternity loses out when they find they are outnumbered by the combined mass of nerds, blacks, gays, Asians, Jews, and traditionally excluded folks in general.)
The really interesting moment in American politics will come if and when the Republican base shrinks in relative size such that it is no longer big enough to win just by turning out in greater numbers. This will happen if/when immigration outpaces Republican efforts to convince Midwestern whites to act like Southern whites. On that day, the Republicans will have to either forge a new coalition - which will be hard, since they'll be so out of the habit - or try for a military coup. I wonder what they'll do.