Liberals would say that their solution is the only acceptable compromise. In a liberal society, everyone — secular and Salafi alike — can freely express their religious preferences. But the notion that liberalism is “neutral” can be accepted only within a liberal framework.

Islamists cannot fully express their Islamism in a strictly secular state. The feelings of alienation that a liberal might feel in a hypothetical “Islamic democracy” are probably not too dissimilar from what the Ennahda leader Rachid Ghannouchi felt when he lived in France as a young graduate student. “The one year I spent in Paris was the hardest and most trying in my entire life,” he wrote in his diary. In his most comprehensive work, “Public Liberties in the Islamic State,” Mr. Ghannouchi attempted to bring Islamic political theory in line with modern democratic norms, but, even here, he falls well short of liberal democracy. This shouldn’t be so surprising: Islamic democracy, however vague, is supposed to rely on a fundamentally different philosophical basis.

If elected Islamist parties have to give up their Islamism, then this runs counter to the essence of democracy — the notion that governments should be responsive to, or at least accommodate, public preferences. Asking Islamists to concede who they are and what they believe is also unsustainable and perhaps even dangerous, pushing conservatives outside the political process.

The implications are clear, if somewhat unsettling. For democracy to flourish in the Middle East it will have to find a way to truly incorporate Islamist parties and, by extension, it will have to be at least somewhat illiberal.

To be sure, in Western Europe and Latin America, socialists and Christian Democrats had to move to the center if they wanted to win elections. But that’s because there was a center. Even in Turkey, which can claim more than 40 years of democratic experience, a strong center has failed to materialize and, if anything, has grown weaker in recent years.

The ideology and ideas of Islamists need to be taken seriously as something deeply and honestly felt. Islamist movements do, in fact, have a distinctive worldview and vision for their societies. If anything, what their detractors say is at least partly true (and it’s something that many Islamists themselves will admit in private): There is, in fact, a “politics of stages” — you concede your Islamist objectives in the short term to strengthen your hand in the long run.

But, as troubling as this may be for Arab liberals, mainstream Islamist movements have been and are likely to remain committed to a democratic process. The scenario of Islamists coming to power through democratic elections only to end democracy has never actually happened. Nor are their beliefs necessarily antithetical to pluralism; Brotherhood-like groups approach Islamic law with flexibility. Far from being textual literalists, their illiberalism tends toward the vague, populist variety. And they’ve come a long way from the 1960s and ’70s, when they saw democracy itself as a foreign import.