I am an Israeli political scientist, where proportional representation (henceforth PR) has been used for legislative elections since the beginning of the state, with a slight departure for direct election of the Prime Minister. Some of what Prof. Tillman writes on his New Reform Club blog post (archive) I agree with, some of this I disagree with, some of it I don't understand
1) "Under proportional representation, the members of the governing coalition having executive power or forming the cabinet is not under the control of the voters. Rather, it depends on the bargaining positions and skills of the elected parties after the election."
It is true that in Israel the legislative elections do not completely determine the makeup of the postelection governing coalition. But nothing in the system stops voters from giving a majority to one party (in the 1950's Ben Gurion's party came close); factions pledging with whom they hope to enter in coalition in order to win votes; or factions uniting pre-election to form what they hope will be a majority list.
Also, in the pure Westminster system, I elect only one representative -- how much more influence, if any, does this give me over the eventual composition of government than as a PR voter?
2) “Proportional representation has advantages if your nation has no external enemies or has farmed out its defense to third parties.“
Israel has PR even though it has serious and desperate external enemies and is not in NATO or an alternative formal alliance structure. It is not obvious to me what price we have paid in foreign and security matters as a result.
3) “On the other hand, where a nation faces actual external threats, proportional representation inhibits decisive action by the executive during war time and other emergencies. Proportional representation makes decisive action during war time and other emergencies difficult because different parties within the governing coalition or cabinet have different interests, will shift blame, and will look to their position in the next poll and in the next election.“
We haven’t seen this very much in Israel, because in fact the parties in cabinet have the same overwhelming interest in the survival of the country. While we have a lot of blame-shifting it occurs, as in the UK and other Westminster countries, mostly among members of the major coalition party. What has prevented decisive action is the absence of consensus as to means of securing peace and security.
4) “proportional representation undermines collective cabinet responsibility”
True, but collective responsibility is only relevant insofar as people get booted and stay booted from cabinet for failure or incompetence. When faction leaders retain power for reasons other than their performance as ministers, they will have to be appeased with cabinet seats even when they aren’t much good as cabinet ministers, and I don’t think it matters much whether the faction is a intraparty fraction or a separate party list.
5) "If the greatest threat your nation fears is a portion of its own citizens, then proportional representation may be the best way to organize your elections."
I am not clear on what Prof. Tillman means by this, but it is true that under PR, “extremists” have an incentive to create their own party, which can then readily be banned, as in Israel and Germany. In the US (which does not have PR), the candidates the establishment loathes can infiltrate major parties, but the institutional tools exist to ban individuals and disenfranchise their supporters -- however, their use has been infrequent and is not yet normalized. I expect that things will be different when the Democrats get simultaneous control of the Presidency and both houses of Congress.
