Can Dundar is the former editor in chief of the leading Turkish newspaper, Cumhuriyet. He is now living in exile.

Last month, Ali Gul, a 21-year-old law student, uploaded a video to YouTube entitled “What is ‘No’?,” a witty explanation of why Turks should vote against the question posed in the Sunday referendum on a new constitution. As he explained, President Recep Tayyip Erdogan wants to end the country’s century-old parliamentary government in favor of a presidential system that would allegedly enable faster decision-making, ensure political stability and streamline decision-making by eliminating the post of the prime minister. If approved, the new constitution will hand Erdogan the reins of the legislative, executive and judiciary branches even as it removes every single brake, replacing them all with a powerful accelerator pedal instead. Erdogan calls this a “Turkish-style presidency.”

Gul offered a sharp response in his video. “Decisions were taken at terrific speed in Gaddafi’s Libya, Assad’s Syria and Saddam’s Iraq,” he observed. “There was streamlined decision-making and there was political stability. But that’s not to say that the end result was particularly great.”

At the end, he asks the cameraman, “What do you think, will I get arrested?” He then replies to his own question: “If the clip is popular, then yes.”

The clip did indeed turn out to be popular — and Gul, in keeping with his prediction, soon received a summons from the authorities. In another video, this time shot outside the prosecutor’s office, he said: “Chances are I will be arrested, but I’m not scared. This country’s young generation deserves freedom, not fear.” A short time later he was taken into custody on charges of “insulting the president,” the same accusation that the government has used against 2,000 other critics. Gul now faces eight years in prison.

Gul’s case is not the only example. If anything, he’s one of the lucky ones. Last week, Huseyin Eser lost his life in an attack by an Erdogan supporter. A shotgun-wielding assailant turned up at a club and yelled, “Is there a son of a bitch here who’s going to vote ‘no’?” When Eser rose to his feet, the man shot him.

This act was foreshadowed, if not inspired, by a statement made by a member of the ruling party on yet another video. “What are we going to do with ‘no’ voters?” he asked, then proceeded to fire a series of shots from the gun he was holding. Two other Erdogan supporters shared a photo on Facebook of themselves posing with guns in a square in the middle of a city: “We’ll be waiting for ‘no’ voters on the streets.” Evidently this was just a step too far even for the authorities, except the two men were released after a brief detention period.

According to officials of the main opposition party, “no” voters on the whole have faced 143 attacks during the campaign. Several opposition rallies have been banned. In one case, the authorities denied “no” campaigners the use of a meeting hall. When the activists finally managed to book one anyway, someone cut the power.

TV channels, which are effectively controlled by the state, have given the government five times more airtime than the main opposition. The leaders and 10 members of the People’s Democratic Party, the third-largest party, are in prison, so their “no” commercial had to be shot using a body double for Selahattin Demirtas, the party’s co-leader. The second spot, which did not show Demirtas, was banned on the grounds that it contravened the constitution.

For those old enough to remember, it is all eerily reminiscent of the referendum that was staged two years after the military coup in 1980. Gen. Kenan Evren, the leader of the junta, similarly accused “no” voters of treason and warned of chaos should the new constitution be rejected. Newspapers were forbidden to use blue, which happened to be the color of the ballot paper used to cast a “no” vote.

Thirty-five years later, Turks are preparing to vote in a referendum under a state of emergency. The country is virtually divided down the middle. Polls indicate a 49-to-51 split between “yes” and “no” — and that’s with a 1 percent margin of error. It is as if two different nations were facing each other at the ballot box, trying to drag the country in two different directions. And in this deadly tug-of-war, despite all the oppression, bans and threats, the “no” camp is still polling 50 percent, which is what infuriates Erdogan most.

A “no” result on Sunday night would effectively declare a halt to this march towards a totalitarian regime. Just like Ali Gul, tens of thousands of arrested opponents, at least 81 journalists in jail, 50,000 sacked civil servants, and the defenders of a secular and democratic Turkey all believe that a powerful “no” vote will mark the beginning of the end for the Erdogan regime.

A “yes” result, on the other hand, will give the president unchecked power. It will bring a return to capital punishment (if Erdogan keeps his word) and a corresponding farewell to Europe, which had made abolishing executions a fundamental condition for eventual Turkish membership in the European Union.

Sunday is a historic watershed for a country torn between a troubled democracy and the gallows. On Sunday, one single word has the power to change the destiny of an entire nation.