Last weekend, tens of thousands of Italians took to at least 100 piazzas up and down the country to demonstrate their support for a measure currently before the Italian parliament, and backed by the governing center-left majority, to provide civil unions for same-sex couples along with full adoption rights.

On Saturday, another wave of demonstrators is expected to flood Rome’s Circus Maximus to oppose that measure, in a rally known as Family Day. It was originally set for the square outside St. John Lateran, for centuries the seat of the papacy, but organizers say they were forced to relocate due to the high number of people planning to take part.

The event is expected to be so big that the Italian train company is offering a 30 percent discount to people traveling to Rome using the code “Family30”, which is standard practice for large national happenings. When backers of the civil unions bill protested in this case, the company apologized but did not withdraw the discount.

The first parliamentary vote on the proposal, known as the Cirinnà bill for the lawmaker who authored it, Monica Cirinnà of the Democratic Party, is set for Thursday. Backers believe they have enough support to pass it, although since parties have indicated that members are free to vote their consciences, hard counts are illusive.

This is Italy, so from the beginning of the ferment, one question above all has loomed over the debate: “Where does Pope Francis stand?”

Early on, it seemed plausible Francis might just sit this one out.

It’s widely known that when Argentina geared up for a national debate over gay marriage in 2010, then-Cardinal Jorge Mario Bergoglio was publicly critical, but privately signaled he’d be willing to live with civil unions as a compromise measure.

In the end that didn’t happen, and Argentina became the first nation in Latin America to legalize gay marriage. Yet memories of the future pope’s position have endured.

When a precursor to Saturday’s Family Day rally was staged last June, the pope’s man within the powerful Italian bishops’ conference, Bishop Nunzio Galantino, was seen as distinctly cool to the idea. The assumption was he was acting with at least the tacit support of the pope, if not his outright blessing.

This time around, Pope Francis abruptly canceled a meeting last Wednesday with Cardinal Angelo Bagnasco of Genoa, the president of the Italian bishops’ conference and a vocal proponent of Family Day. Many took that as a snub, suggesting that Francis wants to keep his distance from the fight.

Two days later, however, Francis reversed course and stepped directly into the debate.

In an annual speech to a Vatican court, Francis issued a blunt warning that “there can be no confusion between the family willed by God and any other type of union,” which was taken by Italians as a criticism of the Cirinnà bill and, at least indirectly, an endorsement of Family Day.

(Also under the heading of “only in Italy,” Cirinnà’s response was classic. She restricted herself to saying, “The pope should be listened to, not commented upon.” In the United States, the gay rights Catholic group DignityUSA was more outspoken, issuing a press release calling the pope’s remark a confirmation that “Pope Francis and other Catholic officials will continue to lead the charge to prevent either civil or sacramental recognition of same-sex relationships.”)

On Monday, Bagnasco gave an annual speech to his brother bishops. He didn’t mention Family Day by name, but did clearly support the right of laity to mobilize.

Catholic laity, he said, “have the duty and the right to participate in the common good, with serenity of heart and a constructive spirit … it’s up to the laity ‘to write divine law into the life of the earthly city,’ assuming their responsibility in the light of Christian wisdom and paying respectful attention to the doctrine of the Magisterium.”

Given all that happened in the run-up to the speech, it’s unlikely Bagnasco would have said that if he suspected Francis wouldn’t have approved, and it was taken as a vote of confidence by Family Day organizers. Recently Tv2000, the network sponsored by the Italian bishops, announced that it will carry the rally live.

There’s already some indication that the latest signals coming from Francis may be changing the political landscape.

Late last week, backers of the civil unions bill presented a packet of modifications, including language clearly distinguishing the relationships from marriage, and also requiring that a family tribunal evaluate all proposed adoptions to be sure they’re in the child’s best interests. Other amendments include that if a couple in a civil union splits up, they will no longer be entitled to use the same last name, another effort to make it different from marriage.

Those revisions, however, have not satisfied the bill’s critics. In the meantime, some backers of the bill are now threatening to vote “no” if it’s watered down any further.

What may account for the mixed signals coming from the pontiff?

1. There’s a key difference between Italy in 2016 and Argentina in 2010. In Argentina six years ago, the alternative to civil unions was full marriage rights; in Italy, no one has put gay marriage on the table, and at least for now, it’s a political non-starter.

Even Cirinnà recently acknowledged that “today the numbers for marriage equality just aren’t there, either in the House or the Senate.”

2. There’s division in the Italian Church. The Italian media has made a great deal of a perceived rupture between Galantino and Bagnasco, and more broadly a divide in the Italian Church, with some dioceses participating heartily in Family Day and others effectively ignoring it.

In that context, Francis may feel the need to demonstrate solidarity with Bagnasco by not undercutting his position.

3. The Church has outsized influence in Italy. Francis has been the Bishop of Rome for almost three years now, and has a deeper understanding rooted in his own experience that Italy is different from the rest of Western Europe in one key respect: For all its travails, the Catholic Church still has significant social capital and packs a political punch.

That doesn’t mean the Italian Church wins all the time; famously, it lost referenda in 1974 over divorce and in 1981 over abortion, and prevailed in 2005 over stem cell research only by persuading Italians not to vote in order to invalidate the ballot.

Yet Mass-going Catholics remain a sizable chunk of the national population and are well represented in both major political parties, and their sentiments have to be at least considered.

Certainly the pope himself still has some political muscle in his own backyard. It was a perceived rebuke from Francis in September, after all, that’s credited with bringing down Rome’s former mayor Ignazio Marino.

Perhaps the calculation on the civil unions proposal — to paraphrase a Star Trek “Borg” reference — is that resistance is not futile.

For now, the pro-family demonstrators planning to turn out in Rome on Saturday can feel that if they don’t have the pope’s explicit endorsement, they’re at least not defying him … and in Italian political life, now as ever, that’s no small thing.