| You're failing to draw the correct analogy in each case. > The difference is that legislative coalitions don't have to be permanent, the way parties are. Just like the parties that make up a legislative coalitions can change, the voters making up a political party can and do change. > Various factions in the legislature can come together for a particular bill, or series of bills on some issue that's relevant to them all. But on something else, they might realign differently This happens all the time on individual bills in a two-party systems as well. ("Crossing the aisle".) But the coalitions forming control of the legislative body rarely change except immediately following elections (in both PR and two-party systems). > Also, even when coalitions are more persistent, the terms are effectively renegotiated every election - party platforms are much more stable. The analog of a particular legislative coalitions in a two-party system is not a particular party but the party in power. And the platform of the party in power changes dramatically when power shifts from one party to another. |