In the same Corriere della Sera/La Nación interview referenced in Mollie's post below, Francis struck an ambiguous note on the topic of same-sex civil unions. Here's NCR's Joshua McElwee:

Asked about same-sex marriage, he responds: "Marriage is between a man and a woman."

"The secular states want to justify civil unions to regulate different situations of living together, driven by the need to regulate economic aspects between people, like ensuring health care," he states, saying he can't identify the ways different countries are addressing the matter.

"We need to see the different cases and evaluate them in their variety," he states.

HuffPo reports on the same interview, including a brief overview of the good news and the not-so-good news from Francis on civil unions:

While he was the Archbishop of Buenos Aires in 2010 and Argentina was on the brink of legalizing gay marriage, then-Cardinal Jorge Mario Bergoglio support legalizing civil unions as a compromise. He also called same-sex marriage “an attempt to destroy God’s plan” and said gay adoption was a kind of discrimination against children. LGBT rights organizations and gay Catholics have hailed Francis' for making more positive statements on gay people during his papacy.

Intriguing.

The Pope makes the essential distinction between civil law and moral norms, pointing to the role of the state in legislating for the common good, not legislating the moral law of the Church in its entirety. This distinction isn't new-fangled, but is clear in the work of Thomas Aquinas, among others. Previous magisterial considerations of legalizing same-sex relationships have seemed to define marriage's social good entirely in procreative terms. Here's one example:

The inevitable consequence of legal recognition of homosexual unions would be the redefinition of marriage, which would become, in its legal status, an institution devoid of essential reference to factors linked to heterosexuality; for example, procreation and raising children. 

That document mentions both civil unions and same-sex marriage, and then-Cardinal Ratzinger roundly condemned both.

Where's the ambiguity in Francis' statement? When asked about same-sex marriage, he reaffirmed that marriage is for straight people only, and made no distinction between civil marriage and marriage in the Church. His comments about evaluating civil union proposals "in their variety" may or may not indicate a willingness to consider same-sex unions that grant rights equivalent to marriage. In other words, is the comment on civil unions part of a response on the question of same-sex unions, or a related-but-different riff on society's role in regulating how the law recognizes people who cohabit whether in sexual relationships or non-sexual relationships? (Tyler Lopez over at Slate insists that the Pope doesn't intend any new approaches to same-sex unions: "Don’t be fooled. Francis is not the first pro-gay pope.")

Even if he does want to open the question of same-sex relationships, it seems to me that the civil unions ship has sailed, at least in the US. By popular vote, legislative action and judicial decree, states are recognizing that civil marriage is a matter of civil rights. A "separate-but-equal" civil union for same-sex couples, while straights get to call themselves "married" has no future in civil law. Meanwhile, the USCCB is doubling down, its subcommittee for the Promotion and Defense of Marriage expressing its support of a proposed constitutional amendment limiting marriage to straight people.  

In a steady increase over the past decade or so, 55% of American Catholics now support gay marriage. A recent Univision poll found a similar level of support for same-sex marriage in the US, and also support in Spain, while the other 10 of 12 nations surveyed report opposition. And there's a strong generational tide at work, too, with young Catholics in favor 18 percentage points more than older Catholics.

Opinion polls don't determine doctrine. They do show the extent to which Catholics are convinced by the Church's argumentation on matters of civil marriage, though. This comes at a time when assorted bishops are calling for a reassessment of Catholic sexual teaching generally, in light of large-scale non-reception of the current teaching. (Here's one recent example.)

What next? At some point, Pope Francis is going to have to settle some of the questions he's raised, whether that of how to enhance women's authority in the Church without ordaining them or that of where he stands now on same-sex civil marriage. Until then, perhaps the best thing Catholics can do is to continue to talk about the matters the Pope raises. With any luck, the surveys on sexual teachings will be the occasion for the fundamental reexamination of sexual teachings, or at least how they're communicated to the faithful.

But the time's short--young people are leaving the Church at an alarming rate, often driven out by what they see as inhospitable teachings. Unlike the response to Humanae Vitae, essentially wide-spread "dissent in place" as Catholics rejected the teaching but continued to practice their faith otherwise, questions of same-sex marriage are public. Interesting times...