Her power in Poland came accidentally. She kept it with stamina – and Facebook.

It was late fall of 1987 in Poland, and the economic and social forces here were fueling tremors that would eventually fell communism across the Soviet bloc.

Among a group of influential men – law professors – at a dinner party one evening was a Communist Party member brainstorming how to throw a bone to pro-democracy activists. The group was tasked with floating a name for a human rights ombudsman; that of legal scholar Ewa Łętowska kept surfacing. A devoted academic who had pumped out two decades of legal research on topics as benign as consumer protections and contract law, she was a respectable but safe choice.

“They said, ‘We want a woman, because women might be easier to manipulate,’” Ms. Łętowska says in an interview in her Warsaw flat, lined floor to ceiling with books and opera records. She laughs at this memory that she possesses only because her lawyer husband was among the men feasting on schnitzel at that monthly table for regulars.

If it was a wallflower they wanted, it turned out to be a miscalculation of historic proportion: They launched a stateswoman.

Her trajectory as Poland’s top human rights thinker, she says, started “loudly, and with a bang” when she was named the country’s human rights ombudsman soon after the dinner party, pioneering the balance between the state and the individual in the waning days of communism.

She was an accidental influencer who, four decades later, now in her 80s, is a sought-after talking head, issuing viral social media posts about democracy. And when voters sent their right-wing government packing last October, a coalition of progressives turned to the wisdom and experience of Ms. Łętowska and her contemporaries.

They’re looking for help to fix Poland’s institutions after the populists turned the country away from the European Union, rolled back civil rights such as abortion, took over the media and judiciary, and questioned the country’s humanitarian aid duties.

Ms. Łętowska value to Polish society cannot be overstated, says Helena Chmielewska-Szlajfer, a sociologist and assistant professor at Koźmiński University. “She’s a living legend, and she has the authority of this wise, powerful woman who set the institutions right in the beginning. She worked on this at a time it was the hardest – the intermediary stage between communism and democracy. And she still has much to say.”

A trip to Hamburg opens her eyes

In 1980, the world saw burly Solidarity unionist Lech Wałęsa leading a revolt against communist authorities for worker rights – and eventually winning a Nobel Prize for it. But it was the progressive technocrats quietly blooming in that politically fertile time who did the less spectacular but essential work of building a democratic legal framework.

Until then, Ms. Łętowska had forged her career as an impartial civil law professor, neither courting the communist regime nor joining the opposition. For instance, she’s on the record saying that the communist martial law of the early 1980’s was “grim” but that she didn’t have enough information to say whether it was “necessary.”

Ms. Łętowska now confidently says she was “a success [as ombudsman]. I was a state official to society, who brought more dialogue, more transparency. At the same time, I didn’t want a political future.”

In an era when one didn’t easily trust one’s neighbor, there was little subversive in her ‘good girl’ youth to suggest she would emerge a strong voice for human rights and democracy. She channeled her incessant curiosity into books and music – a passion that would later drive her to bring in literature and records that were difficult to obtain from behind the Iron Curtain.

On rare study trips abroad — few Polish scholars were trusted to leave the country — she might use German colleagues’ photocopiers to reproduce expensive legal tomes, like handbooks and casebooks on human rights law. Other times she would barter in the West, swapping her sought-after Soviet records for volumes published there.

After law school in the 1960s, she published articles about civic law issues, rising through the ranks as a professor at the Polish Academy of Sciences’ Institute of Law Studies.

A trip to the West – Hamburg, Germany – in the early 1980s was a turning point. She happened upon a demonstration by feminists who were “shabby, with unkempt hair, shouting.” She has forgotten what they were protesting, but from the other side of the street, she could see citizens hurling insults at the women.

“And in between you could see a line of police, with stone faces making sure no one gets hurt, being completely indifferent, and providing this space for demonstrating,” says Ms. Łętowska. “It was the first time in my life I saw police not beating demonstrators – but rather protecting them. This is how I finally understood how things should be.”

”The people of Hamburg would never know how much credit they should take, quite by accident, in my education,” she says.

Staring back at Big Brother

Half a decade after that trip, she was named Poland’s first human rights official, judging the conduct of the state toward its citizens. If Big Brother had once peeked over her shoulder, she was now turning around and staring back.

Should political parties have to register with the state? No, she famously wrote in 1988, when Poland was still under communist rule: “The constitution stated clearly: if parties want to form, let them form. Registration is required only for associations.”

“It was a big deal, when I wrote that,” says Ms. Łętowska says, raising her eyebrows as she lifts a cup of tea.

A few years later, when the police called in state television to film an arrest for demonstrative purposes, as they searched a citizen’s home, she says, “I criticized that. I wrote that basic human rights pacts say privacy should be protected.”

These were important symbolic steps, among many, that demonstrated to the watching public that the regime needed to bend to obey the law — and not the other way around.

After the communist regime fell in 1989, she found herself among the legal scholars helping to modernize the Polish Constitution. Describing the pioneering nature of how they crafted the founding documents, she smiles: “One of my colleagues would be sitting in the library at Parliament … and came up with the now fundamental phrase ‘The Republic of Poland shall be a democratic state ruled by law.’”

In 1999, she was named to one of the nation’s highest courts, and three years later, at age 62 she rose to be a judge of the Constitutional Tribunal, responsible for judging compliance with the constitution of everything from tax reforms to trade agreements. She officially retired from the tribunal in 2011, having delivered public judgments for nearly 100 cases, but continues to mentor law students today.

Her role in shaping history gives her gravitas today as “one of the most important figures defending the rule of law, and also one of the most vocal of all the legal experts,” says Weronika Kiebzak, a legal analyst with Polityka Insight.

Across Ms. Łętowska’s desk passed early, urgent questions about individual privacy and human rights – foreign concepts under communism. Her most forward-thinking ideas came with her insistence that all courts, from the highest down to the most local, should be able to interpret the constitution. “She wanted judges to have more courage – ‘dispersed constitutional control,’” says Ms. Kiebzak, but the idea was never implemented.

That lonely position she staked out decades ago gained fresh urgency when populists took over the tribunal during the last government, leaving no other body with the authority to interpret the constitution.

“My God, how they cursed me” in the 1990s, she says now. “But if they’d taken the trouble to do it right earlier...”

A quieter voice, but still heard

Most days, Ms. Łętowska sips tea in her home, spending hours reading, writing, and fielding media calls. (She turned down four calls during the afternoon the Monitor spent with her.) She will also travel to conferences and public events as an invited speaker.

She’s busy being 84. Harder of hearing, slower of step, she’s keenly aware of her age. ”I have no family; I’m completely alone,” she says. But she indulges her sparky stamina. A trainer comes to her flat several times a week, and she can do 20 “lady pushups.”

Ms. Łętowska also reminisces about her husband, who died in 1999, mourning their record collection, which she is giving away. As her hearing declines, she can no longer fully enjoy it. “It was a very valuable collection,” she says, eyes resting momentarily on an empty space on a bookshelf.

But her nation, rebuilding after stumbles, draws on her elder wisdom today as it did in its early days of democracy. “I’m a lawyer and adviser …. The most I can say is that ‘if you do this, it will work out here but not here,” she says of her legal tinkering.

Her theorizing often plays out across social media, such as in a lengthy Facebook post last summer to her 35,000 followers that was shared hundreds of times. The post started with a nod to her own continuing role as arbiter. “We keep asking what is the law?” she wrote. “What will the expert say?”

Might her most important thinking be ahead?

“As long as I’m mentally fit, I’m here to offer my thoughts,” she says, remaining exactly as she was when she first came into Poland’s consciousness – an accidental influencer.

Piotr Żakowiecki contributed to this report.