A man holds a sign reading “I am furious” during a demonstration last week in front of the Sejm building in Warsaw. (Marcin Obara/European Pressphoto Agency)

If an illiberal government — democratically elected, but determined to change the rules — tries to do something unconstitutional, what can the public do? What can the political opposition do? This is a dilemma we now know from several countries — Russia, Venezuela, Turkey, Hungary, Poland, and possibly soon Greece. The prospects are pretty gloomy, as I’ve argued before, for those who want to stay within the bounds of the law.

One partial answer is peaceful street demonstrations, though that is a frustrating path. Most people don’t have time to stand in a crowd every day or every evening; the chants and speeches can be repetitive; and, more to the point, the government has no obligation to listen. The effort can seem pointless, and it often is — unless it can move the hearts and minds of the leaders of the ruling party. In Poland, over the past week, that’s exactly what just happened.

To briefly recap a complicated story: Poland’s nationalist government had already chalked up a series of constitutional violations and undemocratic decisions, including the politicization of public media, the army, the prosecutor’s office, the civil service and the constitutional tribunal. A few days ago, it passed three laws that would have allowed the current government to dissolve the Supreme Court, fire several dozen judges and replace them with those it preferred.

Mass demonstrations all over the country followed, every night for the past week, in all of the major cities and many small ones, too. Tens of thousands — probably hundreds of thousands — of people sang Pink Floyd, the national anthem, anti-communist protest songs from the 1980s. They stood in front of courthouses with candles. They chanted “Here is Poland” – a riposte to government propaganda that attacked demonstrators as “foreign,” or “traitors,” or “grandchildren of secret police,” paid by George Soros. The majority of the Polish legal community — lawyers, scholars, judges, among them many conservatives — made statements in their support. The sight of so many people on the streets inspired influential foreigners, including Poland’s European Union allies and even the State Department, to comment, too.

The government and the parliamentary majority were unmoved. But Poland’s president, Andrzej Duda, was shaken. Although, unlike his French or American equivalents, the Polish president has very restricted powers, one of them is the ability to veto laws. Duda owes his job to the ruling party’s leader and had been very reluctant to use even that small power in the past. He was directly complicit in the undermining of the Constitutional Tribunal, the decision that began this chain of events.

But the sight of his compatriots on the streets appears to have unnerved him. He has now vetoed two of the three controversial laws. The instant dissolution of the Supreme Court has, at the very least, been postponed.

The story is not over, of course. The lower courts — affected by the one law the president did not veto — are still in danger. The laws will now go back to Parliament, where they may receive nothing more than superficial alterations before being submitted again. The state media, which at one point told its viewers that the demonstrators wanted the Islamicization of Poland, will go on lying about what has just happened.

But at least for a few days, the people who dedicated their evenings over the past week to this cause can congratulate themselves on an achievement. At the end of the day, the point of demonstrations is not to reinforce the views of people who already share them, but to reach across the aisle and convince those who don’t. And, just this once, they succeeded.