Does the bloody Egyptian crackdown on the Muslim Brotherhood mark the beginning of the end of political Islamism? Some seem to think so, citing the ineptitude of Muslim Brothers while they were in power. However, few of those who are trying to answer this question have a clear understanding of what makes political Islam popular in the first place. Hint: it’s not religion.

Sure, Arab countries are religious and Islam is an integral part of their culture. However, in a recent paper, I argue that religiosity is a very weak predictor of voting behavior in Muslim-majority countries. Moreover, looking at data from the Arab Barometer, I find that being supportive of a greater role for Islam in politics means practically nothing in terms of support for specific policy platforms.

So why did Islamists enjoy a significant electoral advantage in the first free elections in Morocco, Egypt, or Tunisia? The answer is twofold—it has to do with the nature of the political environment in emerging democracies and with the history of the Muslim Brotherhood—or its functional equivalents, like Tunisia’s Ennahda movement.

First, economists like Philip Keefer have argued that transitional democracies suffer from a lack of policy credibility. Politicians in such environments have either no history of political activity or have been part of the previous regimes (as a general rule, authoritarian and corrupt ones). In any event, in transitional environments there tend to be few reliable channels of communication between voters and politicians, who are then not seen as credible in making pre-electoral promises about public goods provision or policy.

The genius of the Muslim Brotherhood lies in the fact that, in the aftermath of the Arab Spring, the group—and its political units—was actually able to make credible promises about policy and public goods provision. Unlike practically any other political group, Islamists had a reputation and a brand name.

The Muslim Brotherhood has existed since 1928 and has outlived numerous oppressive regimes. While it was banned from pursuing political activities, Arab governments generally tolerated its involvement in the provision of local public goods, community services, education, or healthcare. In Mubarak’s days, 20 percent of all NGOs registered in the country were run by the Brotherhood. In Jordan, the Brotherhood operates the enormous Islamic Hospital in Amman and the Al-Afaf Charitable Society, which runs collective weddings and provides matchmaking services. In Yemen, the Brotherhood-operated Islah party runs health awareness campaigns, classes in literacy, religious studies, and provides relief payments to poor households.

In a way, the religious nature of the Brotherhood matters. It matters not at the level of theology but rather at the level of industrial organization. Religious organizations are particularly well-equipped to cooperate in the production of club goods and deter free riding through the mechanisms of sacrifice and stigma.

As a result, specifically for poorer Arabs, the Brotherhood represented a very appealing and trustworthy political brand. Yet, once in power, the ineptitude of Muslim Brothers quickly eroded their political support. I have a vivid recollection of Saad Al-Katatni, one of the leaders of the Brotherhood’s Freedom and Justice Party, telling a group of foreign visitors in summer 2011 that he did not know much about the economy. That admission was foreboding of the spectacular economic mismanagement that Egypt saw under Morsi. Furthermore, a credibility-based account of their political success predicts that over time alternative political groups would be able to build reputations and start making credible pre-electoral promises. It was reasonable to expect that the political role of the Islamists would slowly deflate over time.

Unfortunately, the coup and the crackdown on the Brotherhood’s leadership have changed this for the worse. By taking away the political means of participating in public life and purging the political arena of Islamists, the military regime is asking for trouble. Alan Krueger has shown that closing the political process to competition incentivizes religious groups to engage in violence and terrorism as recourse. And remember, groups that are effective in overcoming collective action problems and providing club goods tend to be effective in organizing political violence as well.

It would not be the first time in the Arab world that a crackdown on political Islamism has led to a bloodbath. And given Egypt’s status as the most populous Arab country, the mere thought is chilling.