SILIVRI, Turkey — The protesters converge each day on the village of little tents dotting the landscape here outside a sprawling prison and courthouse. They go about their business of tending a garden of fruits and vegetables, but their primary mission is to denounce the Islamist-inspired government of Prime Minister Recep Tayyip Erdogan.

One man, Riza Yaman, traveled from Germany to spend some time at the camp. “The republican traditions are being compromised and replaced with religious traditions,” he said.

Mr. Yaman is one of dozens of men and women who have been coming here for a little more than a year, angry secularists protesting outside a trial of hundreds of military officers charged with plotting to overthrow the Islamic-rooted government. The case, which has also ensnared journalists, academics and others, has come to symbolize Turkey’s attempt to come to terms with its history of military coups and state-sponsored assassinations. With its harsh judicial tactics and an ever-widening net of suspects, the trial has also illuminated concerns about the accrual of power by Mr. Erdogan and questions about his commitment to democracy.

This is supposed to be Turkey’s time. The country is a rare haven of economic growth and political stability in a region in turmoil. It has been hailed by many across the Arab world as a model for blending faith and democracy. Elected 10 years ago, Mr. Erdogan is poised to become the longest-serving prime minister in the history of the Turkish republic and is planning a 2014 run for the presidency, which he hopes to refashion from a largely ceremonial post to one with strong executive powers along the lines of the United States system.