The New York Times’s article on the populist reaction to the AIG debacle suggests that populism arises whenever a difference of opinion tracks class lines. So for example, same-sex marriage and illegal immigration are called ‘populist’ because elites tend to favor both while the rest of society opposes them:
In 2000, Al Gore’s charge that “powerful interests” blunted working-class aspirations could not win him the White House. George W. Bush prevailed in two elections while courting “values voters,” and in 2004 backed a constitutional amendment to ban same-sex marriage.
Populism, if it is to mean anything, must involve economic and social resntment of the lower classes toward the elites. It doesn’t simply exist whenever the elite takes a different view on a political issue than the rest of society, it arises only when the upper class becomes the political issue. This is generally not the case in the same-sex marriage debate, which is more motivated by religious and moral ideas than it is by an anxiety that a group of fat cats in enriching itself off the backs of the hard-working patrons of Broadway.