Introduction

Three days before the 2015 UK General Election, the Labour Party found itself in hot water: It had to defend a Birmingham campaign event that featured separate seating for men and women. The rally, attended by a majority Muslim audience, was meant to shore up Labour support in Birmingham's ethnically diverse parliamentary constituencies, which are home to more than 200,000 Muslims. Instead of promoting its platform, the Party had to respond to accusations that in aggressively courting the Muslim vote it was turning its back on "a century or more of advancements for women's rights." As pictures of the segregated seating arrangements circulated through the news media, a Labour spokesman meekly countered that "Labour fully supports gender equality in all areas of society and all cultures." Most of the charges were made by political opponents seizing an opening to damage the party just before polling began, but they stung for a reason: Over the last several decades, the Labour Party has made strong appeals to Muslim voters, and in its pursuit of votes it has chosen to empower patriarchal, traditional forces much more than it has promoted egalitarian, progressive voices.

What explains these outcomes? When do parties include groups that provoke opposition from core voters? And when does the inclusion of new groups cause parties to compromise fundamental ideological commitments?

These questions are highly relevant across diverse democracies. In the United States, Republicans and Democrats struggle with how to best respond to a growing Hispanic electorate. Across American cities, already fragile electoral coalitions between whites and blacks are being further tested as this new group enters the fray. In Canada and Australia, both traditional immigration countries, immigrant-origin ethnic minorities remain significantly underrepresented in politics. The same is true in most European countries. Here, problems related to immigrants' sociopolitical incorporation have been very salient. More than 50 million residents living in Western Europe today were born abroad, and many hail from outside Europe. Immigration has transformed the continent's ethnic and religious make-up, and it has stoked fierce controversies about how to best address this new cultural diversity.

The main object of these debates has been the "Muslim Question." Europeans fret that Muslims will not integrate into domestic societies and politics. Because of their religiosity, communalism, social conservatism, and illiberalism, critics allege, Muslims are not ready to participate in the politics of advanced liberal democracies. Anti-Muslim prejudice among voters also runs high. At the same time, parties face growing electoral incentives to garner Muslim support. In many Western European countries, the largest group of naturalized citizens originates from countries where Islam is the dominant religion (see Figure 1.1), a trend that recent refugee inflows from Syria, Afghanistan and Iraq will only reinforce. Muslims are thus beginning to constitute sizable portions of domestic electorates, especially at the subnational level. In Britain, 17 municipalities have Muslim populations that exceed 15 percent of the population, and in 2016 the city of London elected its first Muslim mayor. In Berlin, one in four residents has a migration background, and among this population those with Turkish roots form the largest group. In Cologne, 120,000 residents are estimated to be Muslim, while in Vienna this number stands at roughly 216,000. In Amsterdam and Rotterdam, Muslims make up about 12 percent of the population. In Brussels, nearly one in five residents is of Muslim faith.

If demography is political destiny, parties should take a keen interest in this new electorate. Yet, we observe remarkable variation. Table 1.1 displays Muslim parity ratios across municipalities in Austria, Germany, Great Britain, and Belgium. Parity ratios are measures of representation that divide the share of elected politicians who are Muslim by Muslims' share in the population (i.e., numbers below one indicate underrepresentation, those above one denote overrepresentation). In Austria, parity ratios approach zero. In Belgium, they are close to one. These differences are not driven by the relative size of the Muslim population, which is similar across countries. They are also not the result of varying nationality groups. In Austria, Germany, and Belgium, many Muslim voters have Turkish roots, for instance. In Britain and Belgium, where inclusion rates are high, Muslims have various backgrounds (see Table 1.1). Further, in all four countries Muslim integration has generated fierce controversies, and hostility towards Muslims is widespread.

In addition to differences in the extent of electoral incorporation, parties respond differently to the ideological challenges connected to Muslim inclusion. While some select Muslim candidates who are staunchly secular and egalitarian, others pursue candidates who are decidedly less so. In British cities, for instance, community elders with roots in Pakistan and Bangladesh have for years been winning elections for the major parties on the basis of patriarchal clan and kinship structures. In these contests, men often fill out the electoral registration papers and postal ballots of their wives and adult children, who remain altogether invisible in party politics. Comparable events transpire in the Netherlands. A Kurdish-origin candidate running for the Islam Democraten in The Hague explains his party's recruitment strategy: "Once we have the word of the head of the household, the rest of the family also votes for us. In our culture we do not go against the will of the paterfamilias." The major parties have at times followed a similar playbook.

In Berlin, by contrast, political parties have been faulted for selecting Turkishorigin candidates who are too secular and too progressive to connect with the city's more pious and traditional Turkish-origin electorate. Likewise, when Lale Akgün, born in Istanbul and raised in Germany, served in the Bundestag for the Social Democrats (SPD), she declared on her website that "religion is a private matter" (Religion ist Privatsache), even though she was the party's official "Islam representative" (Islambeauftragte). The SPD had adopted this radically secular slogan at the end of the nineteenth century, only to drop it in 1959 in an effort to reach out to churches and religious voters.

These differences in candidate types have implications for parties' gender balance. Controversies surrounding gender equality are central to the "Muslim Question," so we might expect that parties would be...