Candidate selection procedure in the United States and the European Union
In the United States, a candidate is selected by a primary, a caucus, or a convention. In contrast, there is an intra-party system in much of the European Union. In many parties and countries, the individual party members choose candidates, whereas in others candidates are selected by high-ranking members of the party. It is rare for the general public to select party candidates.
Cartel parties and their selection procedures
This type of political party is essentially a party built around candidates and so it is self-selecting. This ensures that the party elite control whom they put up for election (usually themselves) and it is considered a very crude form of candidate selection. Although full blown cartel parties are rare, with RESPECT and the Union for French Democracy some isolated examples, many mainstream parties exhibit this type of control over who gets elected.
Full Primary systems
This type of system is in place in the US and results in the local populations getting a say in the party’s choice of candidate for election. With this system in place party coherence will suffer as they cannot guarantee that the party elite's choice wins and therefore they will not be able to ensure the loyalty of their candidates as the threat of de-selection will have little or no meaning unlike in the UK. There are very few examples of primary systems in use in Europe. One notable example is the Spanish Socialist Workers Party who held full primary election, which has led to a majority of unsurprising wins for the expected candidates. It has created one major surprise where the party leader was not selected to run for prime minister. This created a degree of instability within the party, which shows the problems of using primary systems in nations where party coherence is an issue.
Restricted Primary systems
This type of system where party members are allowed to voice their opinion regarding candidates is now widespread in Europe. In the United Kingdom the Conservative Party and the Labour Party of the UK also uses this type of system. For the election of constituency candidates in both cases, the local branches can vote on a central list of members and many constituencies hold selections where the candidates assemble in a hall and present themselves and are then voted upon by the members present. Nevertheless, it is important to point out that the nominations for candidates is open to members in many EU states such as the UK, Sweden, Ireland and the Netherlands but the system is subject in all cases to veto and approval by higher party bodies.
There is a wide spectrum of selection procedures that all come from the simple emergence system of Cartel parties to the fully open system of Primary election systems of the US. This spectrum also mirrors the level of party coherence and full primary systems would be found unmanageable in systems where this is essential as the Spanish example demonstrates.