The Encyclopedia of Politics defines anti-clericalism as "opposition to the influence of organized religion in state affairs. The term was applied particularly to the influence of the Catholic religion in political affairs." Historically almost all anti-clericalism in European contexts was effectively anti-Catholicism, in part because the Catholic Church was the largest, most widespread, and most powerful religious institution anywhere.
The Protestant Reformation could itself be considered the largest and most successful form of anti-clericalism in Christian history. Much of the Protestant Reformation was focused on ways individual clergy and church institutions committed so many different abuses.
Of course, these same anti-clerical Protestants created their own new hierarchies and institutions, so their "success" should be treated a bit skeptically. Nevertheless, Protestantism has retained at least some suspicion and distrust of religious institutions.
Anti-clericalism was significant in the philosophies of several major Enlightenment-era figures and it played an important role in the development of secularism in Europe. The French Revolution would have been unthinkable without it's strong anticlerical component.
Anti-clericalism has not, however, had much of a role in American life. Some of the framers of the Constitution were anti-clerical — Thomas Jefferson, for example — but they didn't enshrine their anti-clericalisms in American law or politics.