In presidential systems, electoral alliances are held in both presidential and parliamentary elections. The presidential authority, which holds executive power, has vital importance for political parties. For this reason, parties - whose primary aim is to obtain this position - tend to form an alliance if they cannot get a majority of the votes. Thus, the concept of majority rule in presidential elections make alliances an obligation for countries governed by a presidential system.
The presence of an organic link between presidential elections and parliamentary elections in presidential systems ensures that alliances formed at one election are carried out at the other. For this reason, the general tendency in countries governed by presidential systems is providing alliance both in the presidential and parliamentary elections. In other words, the scope of alliances in presidential and parliamentary elections is interdependent, and the success achieved in one election seems to influence the results of the other.
Since the main actor in the presidential system is the president, the success of this candidate in elections also determines the success of its party in parliament. Called the coattail effect in political science literature, this implies that the presidential candidate’s popularity and electoral success contributes to the success of their party in parliamentary and local elections. This is the case especially when presidential and legislative elections are held at the same time.If there is a significant time difference between the presidency and legislative elections, this effect decreases. The period between the two elections is also another important determinant in the success of alliances.
Another consequence of the coattail effect in terms of electoral alliances concerns minor parties and their election strategies. If the presidential and legislative elections areheld synchronically, the chances of the presidential candidates of minor parties to win the election are reduced. This is because their candidates cannot create a massive effect on society due to their limited popularity. Therefore, these minor parties have a tendency to form alliances with larger parties in order to obtain significant success in elections.
Another element determinant on pre-electoral alliances in presidential systems is the intrinsic political culture of countries. As an extension of this culture, electoral alliances have changing characteristics. For example, in Mexico, alliances have been more common in the last twenty years due to rising political instability following the end of dominant party rule. In related to the effects of instability of the political system, Brazil has very well framed pre-electoral alliance rules in its Election and Political Party Laws. In South Korea, the effects of long-lasting military regimes and strong leadership factors brought about leadership-based pre-electoral alliances formed with the initiation and mutual confidence of the leaders of the parties. As a semi-presidential system, France has witnessed a clear-cut division among political parties on both sides of the spectrum. Parties on the left and right have formed alliances within themselves.
Last but not least, the balance of power among parties forming a pre-electoral alliance is a crucial element. This balance is shaped by their power as a unique actor. Each party in the alliance can contribute to the election success in accordance with its popularity among the general public. At this point, if a party fails to convince its voters that it has achieved necessary gains from an alliance, the party may be negatively affected. For this reason, political parties pay close attention to their achievements and contributions when forming an alliance and observe whether there is any deviance is the balance of power between the two parties.