Turkey’s ruling party has been held up as a religiously conservative but democratic role model for political parties in the Middle East, and it is expected to easily win parliamentary elections Sunday.

But the true test for the ruling Justice and Development Party (AKP) will come after the elections, when it hopes to start rewriting the country’s constitution.

Polls show that Turks are generally satisfied with AKP’s economic successes, but many are wondering if as the region shakes off one dictator after the other, the tide in Turkey is turning the other way. Although the AKP and Prime Minister Recep Tayyip Erdogan have managed to largely allay fears that they may be taking Turkey toward governance under Islamic law, the lingering question of the party’s commitment to democracy weighs heavily on the electorate.

During its nine-year rule, the party has presided over a relatively stable and growing economy. When the AKP came to power in 2002, Turkey was suffering from a banking crisis and double-digit inflation, and foreign debt appeared insurmountable. Now, with a $740 billion economy that is the world’s 16th-largest, the AKP has been concentrating on projects that play well with Turkish voters, such as highway construction, health-care improvements and more public housing projects.

The suspense heading into Sunday’s elections was not whether the ruling party would win, but by how much. According to recent polls, the AKP was expected to take 44 to 50 percent of the vote, with the leading opposition party, the secularist Republican People’s Party, getting 25 to 32 percent. The AKP needs 330 seats in the 550-seat parliament to take a new constitution to a public vote, much like the one it won last year. Whether it can get such a large number of seats depends on the ultranationalist party passing the election threshold and the performance of independent candidates put forth by the Kurdish party.

Erdogan has been urging voters to give AKP the votes necessary for it to get a parliamentary super majority. With such a majority, it may be possible for Erdogan to establish a presidential system. He has said such a system is “what lies in my heart.”

Erdogan, with his fiery temper and defiant style, has not allayed fears that what he wants is perpetual power to rule Turkey. His opponents believe that the inclusive presidential systems characteristic of Western democracies are not the model the AKP has in mind. “From prime minister to president, and president to prime minister out of convenience: This, I’m afraid, is the AKP model,” said Ali Carkoglu, a professor of political science at Koc University, suggesting that Erdogan’s inspiration comes from Russia.

Supporters say a presidential system would not make Turkey more authoritarian. “As long as you have checks and balances, it does not matter which system you have,” said AKP minister Egemen Bagis.

The presidential system would allow Erdogan to govern for two additional terms and see him through to 2023, the 100th anniversary of the Turkish Republic.

The AKP’s list of projects to be realized and benchmarks to be achieved by 2023 — known as “Turkey is ready. The aim is 2023” — focuses heavily on infrastructure projects at which the AKP has proved to be effective, as well as some highly controversial projects, including “Canal Istanbul,” an initiative to create a second strait. “No one is expecting a second Bosphorus. We are expecting a consensus for our future constitution, but I am afraid that’s not their project. They are after a construction project,” Carkoglu said.

Even AKP critics do not deny the economic strides the party has made, but doubt lingers about its democratic credentials.

The rough treatment of protesters by police at Erdogan rallies set off a wave of other demonstrations. Free-speech issues have come into question with a new Internet filtering system set to take effect in August, which would ban pornography as well as content deemed subversive to the unity of the state. Freedom of the press, critics say, has largely been curtailed because of overambitious court cases aimed at the military for plotting a coup. Some journalists have been detained for conspiring to overthrow the government and for belonging to terrorist organizations.

Even people optimistic that a constitution drafted by the ruling party would bring more freedom fear that Erdogan’s personality might make it difficult for Turkey to transition to a presidential system without sliding into authoritarianism.

“This is not an AKP problem; it is a problem of Erdogan’s personality,” said Mustafa Akyol, a columnist for the Hurriyet Daily News. “He likes defiance more than consensus.”

Tuysuz is a special correspondent.