440. Electoral laws (and/or precedents of the EDRBs) often establish additional requirements to be taken into account in drawing up electoral districts, such as the geographic continuity of each district or the principle that, unless there are justifiable objective reasons for doing otherwise, a single urban community – and even more so a single ethnic community – should not be divided. 441. Decisions on the delimitation of electoral districts were once normally considered political questions and therefore not justiciable. However, in 1962 the United States Supreme Court held that malapportionment of electoral districts was justiciable in the case of Baker v. Carr. The Court went on in 1964 to apply the standard of one person, one vote to state legislative elections; in 1973 it reaffirmed the requirement that districts be ‘as mathematically equal as reasonably possible’; and in 1983 it held that congressional districting with a deviation of over 0.7 per cent from the target figure was unconstitutional. Today, more and more EDR systems have followed the US trend and provide for the possibility of delimitation decisions, even when adopted by the legislature, being challenged before the EDRB to review whether they meet the legal criteria. Internal democracy of political parties 442. While some do not consider it appropriate for an EDRB or, as the case may be, an EMB to be involved in the internal life of political parties, more and more countries provide for judicial protection for the electoral right to association, and recognize the right of a political party member to have the party to which he or she belongs comply with its internal party rules. Some of the content of these rules may be laid down in, for example, a political party law, including democratic procedures for selecting party leaders and candidates, and means and procedures that members can use for their own defence within the party if they are subject to a party disciplinary sanction or to expulsion. Even where such provisions are not laid down in party legislation, they may be included in party rules. 443. This trend finds support in the historical trend worldwide to provide judicial protection for electoral rights. The theoretical and legal demands of the model of constitutional democracy under the rule of law are enshrined in the constitutional regimes of democratic governments and various 151 7. Basic elements of EDR systems it is based or influenced by a knowledge of which political party is generally favoured by voters in a particular area. Gerrymandering is the conscious manipulation of the geographic configuration of the electoral districts in order to benefit a particular political party. (The name comes from Governor Elbridge Gerry, who drew up an electoral district in the form of a salamander in Boston, Massachusetts, in order to promote victory for his supporters.)