Center squeeze in the context of "Runoff election"

The two-round system (TRS or 2RS), sometimes called ballotage, top-two runoff, or two-round plurality, is a single-winner electoral system which aims to elect a member who has support of the majority of voters. The two-round system involves two rounds of choose-one voting, where the voter marks a single favorite candidate in each round. The two candidates with the most votes in the first round move on to a second election (a second round of voting). The two-round system is in the family of plurality voting systems that also includes single-round plurality (FPP). Like instant-runoff (ranked-choice) voting and first past the post, it elects one winner.

The two-round system first emerged in France and has since become the most common single-winner electoral system worldwide. Despite this, runoff-based rules like the two-round system and RCV have faced criticism from social choice theorists as a result of their susceptibility to center squeeze (a kind of spoiler effect favoring extremists) and the no-show paradox. This has led to the rise of electoral reform movements which seek to replace the two-round system with other systems like rated voting, particularly in France.

Presidential elections were held in Egypt in 2012, with the first round on 23 and 24 May 2012 and the second on 16 and 17 June. They were the first democratic presidential elections in Egyptian history. The Muslim Brotherhood declared early 18 June 2012 that its candidate Mohamed Morsi had won, the first victory of an Islamist as head of state in the Arab world. It was the second presidential election in Egypt's history with more than one candidate, following the 2005 election, and the first presidential election after the 2011 Egyptian revolution which ousted president Hosni Mubarak, during the Arab Spring. However, Morsi's presidency was brief and short-lived. He later faced massive protests for and against his rule, only to be ousted in a military coup in July the following year.

In the first round, with a voter turnout of 46%, vote-splitting between the major moderate or pro-democracy candidates created a center squeeze, leading to the elimination of Hamdeen Sabahi and Amr Moussa (the likely majority-preferred candidates) in the first round. The elections set the stage for the divisions that were to follow, along sharia and secular lines, and those opposed to and those supporting the former political elite. Islamist candidates Morsi and Fotouh won roughly 42% of the vote, while the remaining three secular candidates won 56% of the vote. Candidates Shafik and Moussa held positions under the Mubarak regime and won 35% of the vote, while Sabahi was a prominent dissident during the Sadat and Mubarak regimes.