Poland had caused many problems within the European Union since the election of the Kaczynski brothers 2 years ago. But the Polish people has reacted accordingly and voiced what a lot of other Europeans thought, by giving a crushing majority to the opposition pro-EU party.

The Kaczynski brothers were such a threat to Poland's image in Europe that this early election prompted the highest turnout in a Polish election since the fall of communism in 1989.

More info here :
BBC News : Polish opposition set for big win