More Support for Removing the Pluris

This time it comes from Leo Zuckermann:

In political science there exists "Duverger's law" in honor of the French sociologist who elaborated it. This thesis says that majority electoral systems, where the legislature is composed only of plurinominal legislatures, generates bipartisanship. In these systems the first past the post principal is followed: the candidate that obtains the post is he who wins even if it is by only one vote in his district. This polarizes the competition between one party on the right and one on the left. The clearest examples are the United States (Republicans and Democrats) and the United Kingdom (Conservatives and Laborites). In a system like this it is practically impossible the survival of a third party.

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A clear example is the 1983 election in the United Kingdom. The Conservative Party won 42 percent of the vote but it obtained 61 percent of the seats in Parliament. As such, Margaret Thatcher had a very comfortable majority with which to govern. She took advantage of it to carry out an agenda of aggressive change. Hers was, without a doubt, a strong government.

He goes on to say that the system holds down the Liberal Democrats, who won 22 percent of the vote in 2005, but wound up with just 10 percent of the seats. I find the thrust of this argument much more convincing than that of Pedro Ferriz de Con, which basically amounted to the simplistic claim that the plurinominals are dead weight holding back the rest of the legislature. But I remain unconvinced, for a couple of reasons: first, any attempt to install a British system in Mexico would force the PRD to play the role of the Liberal Democrats --i.e., receiving a percentage of seats half as large as their vote total-- and could precipitate a potentially serious political crisis. Second, I don't know about Britain, but the tradeoff for a uninominal system in the US is legislators whose focus is their district first, and the country second. For a federal congress, said focus is the opposite of what it should be, and it is not worth the benefit of ditching the plurinominal legislators. Third, a bipartisan system is not incompatible with plurinominal representatives; you'd just need to recalibrate it so that it disproportionately benefited the top two finishers nationally.