The law is meant to ensure order, deterring only the most provocative acts, says Said Ferjani of Al Nahda's political bureau. There have been several riots in the past year over art and films deemed blasphemous by ultraconservative Salafis.
Still, such moves have some Tunisians fearing that religiously driven governance will erode the free speech they consider a central gain of their revolution. In June a court upheld prison terms for a cartoonist who caricatured Muhammad and a man who posted the images online. Both were convicted of "offending public morality."
For other Tunisians, however, revolution means the freedom to support a more Islamic society. Under Zine El Abidine Ben Ali, thousands of pious Muslims were jailed or driven into exile.
Al Nahda hopes to reassure everyone. "Tunisian society wants something light; you're neither forbidden to drink, nor from going to the mosque," says Sami Triki, a Tunis lawyer and member of Al Nahda's political bureau.
This is partly because Tunisia is shaped not just by its Arab-Muslim roots, but by its years as a French colony and by its first president, the secularist modernizer Habib Bourguiba.
"Western culture feels closer than Arab culture. It's in our clothes, our technology, in the fact that we speak French," says Khaoula Arfaoui, a shop employee from a working-class Tunis neighborhood who voted for Al Nahda. "But we also pray; we fast for Ramadan."
Ms. Arfaoui says she wants the state to encourage Islamic values, but not issue orders or prohibitions. "It should be more about education. Even our Lord told the prophet Muhammad he should not use force," she says.
While Al Nahda's leaders echo that message, not all Tunisians agree. Some Al Nahda voters have even joined Salafis in calling for sharia to be cited in the constitution as a principal source of law.