Prominent blogger Matthew Yglesias recently expressed surprise that most politicians are willing to sacrifice the public good in order to hold onto power:
I've come to be increasingly baffled by the high degree cynicism and immorality displayed in big-time politics. For example, Senators who genuinely do believe that carbon dioxide emissions are contributing to a global climate crisis seem to think nothing of nevertheless taking actions that endanger the welfare of billions of people on the grounds that acting otherwise would be politically problematic in their state. In other words, they don't want to do the right thing because their self-interest points them toward doing something bad. But it's impossible to imagine these same Senators stabbing a homeless person in a dark DC alley to steal his shoes . . .
Making it all the odder, the level of self-interest at stake isn't all that high. Selling the public good down the river to bolster your re-election chances isn't like stealing a loaf of bread to feed your starving children. The welfare rolls are hardly stocked with the names of former members of congress. Indeed, it's not even clear that voting "the wrong way" poses particularly serious threats to one's re-election. But even if it did, one might assume that people who bother to dedicating their lives to securing vast political power did so because they actually wanted to accomplish something and get in the history books, perhaps, as one of the big heroes of their era.
Tyler Cowen and Arnold Kling correctly point out that professional politicians are likely to be individuals who place a high value on power and prestige. To such people, there is a lot at stake when they risk losing their positions. True, they won't starve. But they will lose the power they greatly value and have dedicated their lives to achieving. Yglesias notes that the same politicians who routinely sacrifice the public interest to preserve their positions wouldn't think of committing murder. That, however, is at least partially because in the US and other liberal democracies committing murder usually destroys a politician's career rather than bolsters it. In countries where killing people often does advance your political career, (think any of numerous Third World states where political leaders can get ahead by killing or repressing political opponents), the political class is indeed filled with murderers.
One might still ask why the power-seekers tend to predominate over those who place a higher value on the public good. The key explanation is selection effects. A politician willing to do anything to take and hold on to power will have a crucial edge over an opponent who imperils his chances of getting elected in order to advance the public interest. The former type is likely to prevail over the latter far more often than not. This is especially true in a political environment where most voters are often ignorant and irrational about government and public policy. Candidates have strong incentives to pander to this ignorance and exploit it in order to win elections. Those unwilling to exploit public ignorance because they place the public interest above political success are likely to be at a serious disadvantage relative to their less scrupulous opponents. Thus, politicianswho value power above other objectives are more likely to get into office and stay there. As economist Frank Knight wrote back in the 1930s, "[t]he probability of the people in power being individuals who would dislike the possession and exercise of power is on a level with the probability that an extremely tender-hearted person would get the job of whipping master in a slave plantation."
Finally, Yglesias suggests that a politician who prioritizes the public good could potentially be remembered as one of the great political "heroes" of the age, which should give our leaders a strong incentive to prioritize the public good. There are three problems with this argument. First, you are unlikely to become a great political hero unless you get into power and stay there for a considerable length of time. Doing so usually requires prioritizing political survival. Second, cynical political manipulators also can be remembered fondly by history if they build a successful political coalition (think FDR or Disraeli). Finally, and most important, the odds of being remembered by history as a great political hero are generally very low, even if a politician makes it his top priority. By contrast, the average politician stands a much better chance of getting a position of power and prestige in the here and now, if he puts his effort into that. For most politicians, a 50% or even a 10% chance of fame and power today is more valuable than an 0.1% chance of being remembered as a great hero years after they die.