Opposition party Nowoczesna leader Ryszard Petru, center, and other parliamentarians hold cards that say “#Free Media in Sejm.” (Marcin Obara/European Pressphoto Agency)

From Dec. 16 to Jan. 11, 10 members of parliament occupied the plenary hall of the Polish parliament (called the Sejm). The unprecedented blockade began with a protest against the right-wing ruling party’s ban on allowing the news media in the building. It continued as a way to object to what many have seen as an uncertain fate for the rule of law in Poland — including plans for a far-reaching reconstruction of the court system that could endanger the nation’s hold on democracy.

Until recently, Poland and Hungary were seen as examples of successful transitions to democracy. Each emerged from behind the Iron Curtain after the Soviet Union dissolved in 1989. Each is now ruled by a right-wing party that is steadily shaving away those new democratic institutions and norms — and which is explaining its crackdown in part by pointing to past failures to fully clean house after communism.

So what is decommunization?

Before Poland’s populist Law and Justice (PiS) party came to power, Poland had largely forgone “transitional justice.” That’s when a newly democratizing nation comes to terms with former authoritarian elites. In South Africa, that involved the “Truth and Reconciliation” hearings.

In post-Soviet countries, one common approach is called “lustration” and “decommunization.” In that approach, the new democracy publicly brings to light public figures who had collaborated with the communist secret police — and then removes from public office any former high-ranking members of the Communist Party, including members of the court system.

In my book “Skeletons in the Closet: Transitional Justice in Post-Communist Europe,” I argue that both “lustration” and “decommunization” have a tenuous relationship with the principle that there can be no crime unless a law was in place against the action, known as nullum crimen sine lege.

Here’s the problem: Both approaches are in sharp conflict with the principle of judicial independence. How can a democracy reconcile that principle with any effort to expose judges as having collaborated with communists at a time when communism was the law?

That’s the reason both Poland and Hungary refused to launch full-scale transitional justice programs — which at the time brought praise from the international legal community. But those unsettled scores may now be a pretext for backsliding into authoritarianism.

Here’s the background in Poland

For instance, Poland tried to avoid violating nullum crimen sine lege with the idea that instead of punishing former communist spies and high-ranking security officials, it would instead demand that candidates for public office submit affidavits testifying whether they had collaborated with the former authorities. These affidavits would then be checked against existing evidence. Those who lied about their past would be punished with removal from office — not for being a communist spy, but for lying.

Between 1997 and 2015, a series of Polish democratic governments convened lustration departments that received 370,000 lustration declarations to verify against files of the former secret communist police files. Of these declarations, to date roughly 60,000 have been reviewed, and 881 were directed to special lustration tribunals. Out of these, 530 declarations were declared false and the liars exposed. Among them were 430 politicians, 22 attorney and eight professors. These and other revealed collaborators were declared permanently ineligible for government office.

However, when a series of Polish governments tried to do the same with judges, those efforts were halted by the Constitutional Tribunal — the equivalent of the U.S. Supreme Court — on the grounds that the judiciary must remain independent from other branches’ interference.

That has given PiS an opening.

During the 2015 campaign for parliamentary seats, PiS argued that failing to purge the judiciary of former communists and collaborators is a caricature of justice — and that the court system is precisely where communism remains entrenched.

PiS says it plans to “end Poland’s post-communist era” by transforming the court system. Poland’s court system is a complex four-level hierarchy with regional, district, appellate and the highest court. The Constitutional Tribunal stands separate from this hierarchy, evaluating the government’s legislation.

In the October 2015 election, PiS won with only a minority of the vote but took an absolute majority of seats in the legislature, Poland’s first single-party majority cabinet since 1989. PiS has since undertaken several changes widely perceived as heading away from democratic norms.

For instance, the Constitutional Tribunal is soon scheduled to evaluate the PiS’s legislative restrictions on public gatherings and the national security bill permitting wiretapping and granting government access to phone records and electronic data to preempt criminal activity.

So perhaps it’s no surprise that PiS targeted the Constitutional Tribunal for changes as soon as it took power, in ways that, according to some critics abroad, border on authoritarian backsliding.

PiS’s President Andrzej Duda refused to swear in three justices who had been elected in the previous term to replace judges whose terms were running out. That move was appealed to the Constitutional Court itself, which upheld the constitutionality of the election of the three justices. The PiS cabinet’s chief of staff refused to publish the Constitutional Tribunal’s verdict, hoping to invalidate it. But after the High Court ruled that the Constitutional Tribunal’s verdicts have full force of the law from the moment they are handed down, regardless of publication, the three justices joined the bench.

PiS continued to deny the new judges’ legitimacy and elected its own three candidates. These judges (referred to as “extras”) also joined the bench. The chief justice refused to appoint them to sit on panels.

In the next step, PiS passed two bills that shortened terms of the judges of the Constitutional Tribunal and appointed a PiS loyalist, Julia Przyłębska, as chief justice. Poland’s National Council of the Judiciary had evaluated — and rejected — Przelecka, saying she lacked the qualifications for a post in the appellate court. What’s more, she began her judicial career in communist Poland, making her exactly the kind of judge PiS promised to get rid of.

As a result, the European Union is evaluating the status of the rule of law in Poland.

Here’s what the right-wing PiS party has promised to do next

PiS plans to eliminate one or both middle layers of the court system, the regional and appellate courts, without replacement. Judges over 65 would be forced to retire; those younger would need to be reappointed to courts that survive the reform, possibly after being vetted by a special commission.

Finally, PiS says it will make it easier for the government to impose disciplinary actions on all judges, a move that the Constitutional Tribunal threatened to strike down. Currently, disciplining judges is handled by the National Council of the Judiciary — an independent body — which makes recommendations that are then carried out by a special ombudsman for discipline.

PiS would transfer this power to the minister of justice and would expand potential disciplinary measures, including salary cuts of up to 20 percent and stripping retired judges’ pensions.

How many divisions does the Constitutional Court have?

In countries with a long-established tradition of judicial independence, constitutional courts do not need to intervene much to exert their power. Sheer anticipation of their intervention is enough to prevent legislatures and executives from attempting to enact unconstitutional legislation. But in young democracies, the incentives are different. The anticipation that key pieces of legislation might be overruled can tempt governments to weaken political institutions that stand in the way.

Poland is hardly an isolated case. In 2013, Hungary’s right-wing Prime Minister Viktor Orban passed constitutional amendments that ignored decades of verdicts from the constitutional court, and eventually took down the court itself. Like PiS, the Orban-led Fidesz-Hungarian Civic Alliance came to power on an anti-liberal agenda that promised to clear away the influence of former communists.

It is indeed ironic that Poland and Hungary, after accolades for peaceful and efficient transitions from communism that avoided harsh justice, now appear to be backsliding into hybrid regimes that disregard the rule of law.

Monika Nalepa is associate professor in the department of political science at the University of Chicago.