In the nineteenth century, in nearly every country that delimited districts, legislative approval was required before a redistricting plan could be implemented. Recent reforms designed to remove politics from the redistricting process have reduced the power of legislatures to approve redistricting plans. In many countries today, the legislature plays only a limited role or no role at all in the redistricting process. However, some countries do require executive approval, rather than legislative approval, before a redistricting plan can be implemented. While this removes the decision from legislators--those who directly benefit from the districting plan--it still leaves the redistricting process open to charges of political influence.
In the majority of countries that assign election management bodies the task of delimiting constituencies, the election commission serves as the final authority; the approval of the legislature or executive is not required to implement the delimitation plan. This is less true of boundary commissions – more often than not, a constituency plan proposed by a boundary commission must be enacted by the legislature (or signed by the executive) before it can be implemented. However, in New Zealand, for example, the final plan of the Representation Committee, once published, cannot be changed or appealed. Since 1983, Australia’s augmented Electoral Commission has had the same power. The constituency boundaries created by the Delimitation Commission in India are also final.
In other countries, the legislature can debate and, possibly, even delay the enactment of a commission's plan, but it cannot modify the plan. In Canada, for instance, the 1964 Electoral Boundaries Readjustment Act removed the responsibility for redistricting from the Parliament and gave it to independent electoral commissions in each province. Parliament is permitted to consider plans produced by the commissions but has no vote on their implementation. Parliament used this provision to delay the implementation of plans, however, prompting a change in the law--there is now a sixty day limit on Parliamentary debate and consideration.
In the United Kingdom, the final proposals of the four Boundary Commissions take effect only after an affirmative vote by Parliament. But Parliament's power to accept or reject a plan is a formality. It has almost always affirmed commission proposals; to do otherwise would be viewed as "political." The only two exceptions were in 1948, when Parliament proposed the addition of seventeen seats for under-represented urban areas, and in 1969, when Parliament delayed the implementation of a redistribution plan on the grounds that impending changes to local government boundaries would render the plan obsolete. Conservatives viewed both of these actions by the Labour government as political.
Some countries have provisions requiring the legislature to either accept or reject the proposed delimitation plan, but specifically do not grant parliament the authority to modify the plan. Examples of this approach include Malaysia, Mauritius, and Papua New Guinea.
The United States is the anomaly with regard to legislatures and the adoption of redistricting plans. Most states assign the task of federal redistricting to the state legislature. The few that assign the task to an agency or a commission still require an affirmative vote of the state legislature to enact a redistricting plan.
Conclusion
Allowing the legislature to accept or reject a plan--let alone create it--opens the redistricting process up to charges of political bias. In fact, many plans adopted by legislatures do favour one political party over others. Still, plans drawn by neutral commissions can also produce politically biased election outcomes, however unintentional.
