If rank-and-file members of the Labor and Liberal parties have a say in choosing their parliamentary leaders, as Kevin Rudd wants to have happen in the ALP, there are some potentially significant consequences.
Because of his support for an Australian republic, Malcolm Turnbull might forever be ruled out from becoming Liberal leader. And Julia Gillard, for whom many Labor Party members felt a degree of sympathy, might never have been replaced by Rudd.
Changing how party leaders are picked also has implications for the parties' policies. That's because party members often have policy positions stronger and more ideological than those of their elected MPs. Any MP aspiring to be leader of their parliamentary party and aiming to get the votes of rank-and-file members will have to take this into account.
The phenomenon whereby the opinions of MPs are more moderate than those of party members is well known. It's called May's Law of Curvilinear Disparity. In 1973 in a seminal research paper, University of Queensland academic John D. May explained that because MPs need to get elected they therefore hold opinions closer to those held by the average voter than to those held by party members.
Politicians and party members have quite different motivations. Politicians seek elective public office and they get the power and the prerequisites that come with office. Many think of themselves as ''a national legislator first and a partisan second'' — and the skills they prize are technical knowledge, rhetorical ability and parliamentary adroitness, regardless of the issue they're taking about.
Rank-and-file party members are quite different. Those who don't seek preselection for themselves have the prospect of few tangible rewards.
Our system of voluntary and amateur political parties ''attracts zealots in the party cause, and particularly so at the local leadership level, where there are many routine political chores which only the devoted are likely to perform. Principles, not professional careers, are what matter here.''
Party members have long been a nuisance to party leaders. At the beginning of the 20th century the British Conservative politician Lord Hugh Cecil said his party activists were often ''knots of vehement, uncompromising, and unbalanced men''. On the Labour side, Sidney Webb said his cadres were ''unrepresentative groups of nonentities dominated by fanatics and cranks and extremists'' who risked their party's chances of winning office.
George Washington in his Farewell Address in 1796 spoke in theoretical terms about the need to for leaders in democracies to control the extremists in their own ranks in order to achieve stable government. There's also a practical reason why MPs tightly manage both their policy and personnel. It comes back to the desire of MPs to win elections. As the American political scientist Herbert Kitschelt has noted ''when party activists internally democratise parties and remove the leadership's freedom of appeal to marginal voters'' it becomes difficult for MPs to balance the radical ideological programmes sought by the membership with the preference of swinging voters towards the status quo.
When Robert Menzies founded the Liberal Party in 1944 he made sure that party members had no say over policy. Partly he wanted to limit outside influences, but it was also to control the ideologues in the membership. For Menzies, having party members choose the parliamentary leader would have been even more dangerous than letting them decide policy. Menzies' legacy continues through to this day.
A few months ago when Liberal party members in Victoria wanted to debate a motion at their state council to sell the ABC, Tony Abbott said no.
Giving all party members a say in policy and in choosing the parliamentary leader is good. The result would be more diversity and debate.
Whether Kevin Rudd, or indeed any political leader, actually wants that sort of outcome is doubtful. If only Rudd had not announced his plan in the midst of his ersatz election campaign, then the public might be less cynical about his motives.