TWO DELEGATIONS of Islamist politicians, from Tunisia and Egypt, were in Washington last week on what amounted to charm offensives, aimed at reassuring Americans that their movements are not threatening. The envoys from Tunisia’s Ennahda party and Egypt’s Freedom and Justice party, an offshoot of the Muslim Brotherhood, each pledged to respect democratic norms and the rights of women and minorities. Each supported U.S. aid to their countries, including military aid.

But one group was more persuasive than the other. The Tunisian representatives, whose party leads a three-member governing coalition, made clear they will not seek to impose Islamist precepts — like sharia law — on their country even if they have the majority support to do so. The party announced last month that in ongoing deliberations on a new constitution, it would propose defining Tunisia as an Arab country “whose religion is Islam,” with no mention of sharia.

“We are seeking a constitution for all Tunisians which is based on consensus and not majority rule,” Mondher ben Ayed, an adviser to Prime Minister Hamadi Jebali, told us.

The Muslim Brotherhood delegation also expressed a wish to build consensus and maintain stability; its members said that a Freedom and Justice party government would focus on rebuilding the economy and would welcome U.S. aid. But when they discussed writing a new constitution, the Egypt Islamists’ stance was majoritarian: The large parliamentary bloc elected from religious parties, they said, makes it appropriate for those parties to dominate the constituent assembly writing the constitution.

Domination of that body by the Brotherhood and more extreme Salafist parties has caused a quarter of its members — including secular liberals, Christians and even representatives of the venerable Al-Azhar Islamic university — to withdraw their representatives. As for sharia, the Brotherhood’s presidential candidate, Khairat el-Shater, who was nominated last week despite the movement’s earlier promise not to pursue the presidency, was quoted as saying that the application of sharia in Egypt is his “ultimate goal,” though he did not mention a timetable.

Both Islamic movements deserve some benefit of the doubt. They have won free and fair elections, sought to strike deals with secular opponents and are reaching out to Washington. The Obama administration has rightly responded by proposing $100 million in direct aid, as well as loan guarantees, for the Tunisian government. Wrongly in our view, it has renewed military and economic aid to Egypt even before the scheduled transition to a democratic government this summer.

Tunisia offers the more promising model. Election results notwithstanding, it seems clear that the vast majority of Egyptians as well as Tunisians seek economic progress and respect for human rights, and not a theocracy. Secular citizens and minorities, who make up a large part of the population, will not accept discrimination. Islamic movements will succeed in government, and retain their following, only if they recognize those realities.