Clay Risen has a piece in Democracy: A Journal of Ideas about how a trip to Germany convinced him that liberals are wrong to pine for a parliamentary political system. I had a lot of problems with the piece, but to just render a simple objection he totally runs together the idea of a “parliamentary” system of government with the idea of a political system with more than two large political parties, such that assembling a parliamentary majority typically requires the construction of a multi-party coalition. I wouldn’t go so far as to call these unrelated issues, but they’re definitely different. Certainly the question of where a country falls on the presidentialism-parliamentarism spectrum doesn’t seem to have a clear relationship with how multi-focal its party system is.
I also think it’s weird for a piece that dwells so heavily on how the rise of Die Linke has fractured the left to not even mention that it was just nine years ago that George W Bush beat Al Gore thanks to left-wing defections to Ralph Nader, while Gerhard Schröder and Joschka Fischer were leading a successful red-green coalition government.