of coalition building and distribution of power were as a two party state is winner takes all.

The coalitions are built within the two party system. From time to time, one of the two party's will implode and reform pulling in more special interest groups to build a majority.

Shared democracy keeps those coalitions on the outside while a winner take all system incorporates them within the two party's.

on edit. When that happens in the US, it is called a realigning election which just means the players move from one party to another when the music stops. The best example in modern times was when busing to integrate schools came on line in the late 60's and early 70's that expedited the white flight from urban centers to the suburbs. The Republicans became the law and order party, meaning we will protect you from the colored people, and everything shifted. It's happening again as the racial divide is not as relevant as it was in the 70's thru the late 90's. 9/11 just prolonged the realignment.