A nice summary on voter irrationality from Larry Bartels:
"While voters are busy meting out myopic, simple-minded rewards and punishments, political observers are often busy exaggerating the policy content of the voters’ verdicts. The prime example in American political history may be the watershed New Deal election of 1936. Having swept into office on a strong tide of economic discontent in 1932, Franklin Roosevelt initiated a series of wide-ranging new policies to cope with the Great Depression. According to the most authoritative political scholar of the era, V. O. Key, “The voters responded with a resounding ratification of the new thrust of governmental policy”—a stunning 46-state landslide that ushered in an era of Democratic electoral dominance.24
The 1936 election has become the most celebrated textbook case of ideological realignment in American history. However, a careful look at state-by-state voting patterns suggests that this resounding ratification of Roosevelt’s policies was strongly concentrated in the states that happened to enjoy robust income growth in the months leading up to the vote. Indeed, the apparent impact of short-term economic conditions was so powerful that, if the recession of 1938 had occurred in 1936, Roosevelt probably would have been a one-term president.25
It’s not only in the United States that the Depression-era tendency to “throw the bums out” looks like something less than a rational policy judgment. In the United States, voters replaced Republicans with Democrats in 1932 and the economy improved. In Britain and Australia, voters replaced Labor governments with conservatives and the economy improved. In Sweden, voters replaced Conservatives with Liberals, then with Social Democrats, and the economy improved. In the Canadian agricultural province of Saskatchewan, voters replaced Conservatives with Socialists and the economy improved. In the adjacent agricultural province of Alberta, voters replaced a socialist party with a right-leaning party created from scratch by a charismatic radio preacher peddling a flighty share-the-wealth scheme, and the economy improved. In Weimar Germany, where economic distress was deeper and longer lasting, voters rejected all of the mainstream parties, the Nazis seized power, and the economy improved. In every case, the party that happened to be in power when the Depression eased went on to dominate politics for a decade or more thereafter. It seems far-fetched to imagine that all these contradictory shifts represented well-considered ideological conversions. A more parsimonious interpretation is that voters simply—and simple-mindedly—rewarded whoever happened to be in power when things got better.
Stupid? No, just human. And thus—to borrow the title of another current bestseller, by behavioral economist Dan Ariely—“predictably irrational.” That may be bad enough."