AHMED MAHER, one of the leaders of Egypt’s 2011 revolution, supported Islamist Mohamed Morsi in last year’s presidential election because he believed Mr. Morsi’s victory over a military-backed candidate would be more likely to consolidate democracy in their country. But during a visit to Washington last week, Mr. Maher told us that Mr. Morsi had betrayed him and his April 6 Youth Movement. “They lied, they broke promises, they killed members of April 6,” Mr. Maher said. Mr. Morsi’s government, he said, increasingly resembled that of former strongman Hosni Mubarak: “They only seek power.”

Mr. Maher’s strong charges soon were substantiated by another transgression: Upon returning to Cairo from the United States on Friday, he was arrested at the airport. The 32-year-old, who founded the April 6 movement in 2008 to organize protests against the Mubarak regime, was charged with inciting a protest in March against Mr. Morsi’s interior minister. His transfer to a high-security prison quickly provoked a backlash both in Cairo and in Washington, and on Saturday authorities backed down. Mr. Maher was released, his case was transferred to a lower court and Mr. Morsi’s office and political party repudiated the airport arrest.

That retreat still left Mr. Maher facing charges, according to the state news agency, of “resisting the authorities, insulting the police, gathering and obstructing traffic” — counts frequently used by the former dictatorship against public demonstrations. It offered new cause for concern about a government that repeatedly has proclaimed its commitment to both democracy and compromise with its opponents even as it prosecutes critics and prepares repressive new laws.

Mr. Maher’s youth movement has resisted the polarization that has overtaken Egyptian politics in the past year. Though its leaders are secular liberal democrats with left-leaning views, they supported Mr. Morsi after obtaining direct assurances from him that he would seek consensus on the terms of a new constitution. The president broke that commitment in November, when he granted himself absolute power in order to force through a constitution favored by the Muslim Brotherhood. Meanwhile, a state prosecutor Mr. Morsi appointed in what opponents contend was another illegal maneuver has been bringing charges against critics, including journalists and organizers of demonstrations. A legislative body dominated by the ruling party has given preliminary approval to a law that would eviscerate Egypt’s civil society, shutting down almost all government-watchdog and human rights groups.

Mr. Morsi’s spokesmen have asserted that he does not favor the political prosecutions and that the government is preparing a new version of the civil society law. But the president has not removed the prosecutor he appointed nor met other reasonable opposition demands, such as the correction of a gerrymander of electoral districts legislated by his party.

Mr. Maher opposes counterproductive strategies embraced by other opposition leaders, including a boycott of future elections or support for a military coup. But he warns that the United States is repeating past mistakes in Egypt by appearing to tolerate Mr. Morsi’s consolidation of power. “If you want to support democracy, say we are here in Egypt to support democracy, not whoever is in office,” Mr. Maher says. That’s advice the Obama administration should heed.