DUBLIN Three weeks before Irelands historic vote on whether to legalize abortion, which happens Friday, I sat in a noisy pub here with Gavin Sheridan, an Irish data journalist and transparency campaigner who has closely followed the referendum. Sheridan fancies himself something of an election-whisperer, having predicted Donald Trumps 2016 victory after a road trip through West Virginia, Pennsylvania and Ohio, and he spoke with an ominous urgency about the coming vote.

The conventional wisdom may have it wrong, he worried. The polls suggest the referendum will be an easy walk for abortion rights supporters. A recent survey showed 56 percent of voters said theyll vote yes to repeal the 8th Amendment a near total ban on abortion, except to save the life of the mother while roughly a quarter (27 percent) said theyll vote to keep the ban in place.

But Sheridan wasnt convinced. The no side, he explained, was running a much stronger and better-funded digital operation. Money was pouring into its coffers from God knows where. Irish voters were being bombarded with anti-abortion ads on Facebook and Youtube, some of which were carefully targeted at undecided voters. If you knew where to look, you could discern the fingerprints on the no side of American anti-abortion groups and some of the same firms who contributed to the surprise outcomes in the Trump election and Brexit.

He walked me through one example. An anonymous Facebook page and website called Undecided on the 8th purported to offer voters neutral information on the referendum. But its purpose was to entice undecideds to identify themselves so that anti-repeal groups could target them before the vote. Sheridan traced the origins of that page and was able to link it to at least two U.S. Catholic groups The Community of St. John and New York Franciscan Friars of the Atonement.

Facebook and Google tried to crack down on foreign influence in the Irish referendum last week, banning all ads on the issue from outside Ireland to help ensure a free, fair and transparent vote. But those decisions havent stopped U.S. groups from helping out behind the scenes. Storyful, a Dublin-based social media intelligence agency where Sheridan used to work, reports that only 37 percent of digital ads for the anti-abortion rights campaign are being managed solely from inside Ireland, compared with 81 percent of ads on the abortion rights side.

Sheridan was nervous, and so were the leaders of the pro-repeal campaign.

Im a very optimistic person, and I always think well win this if we do the work, said Colm OGorman, executive director of Amnesty International Ireland, in an interview before Facebook and Google handed down their bans. But theres a lot of concern about the impact of a very, very, very well-resourced and targeted digital campaign being launched by the other side, and were really anxious about it. There has been a big concern here, understandably given what we saw in the last U.S. general election and in the Brexit campaign about influence, and how influence might be exacted online in quite disingenuous ways.

The pro-repeal campaign in Ireland has had to raise money largely from inside the country, especially after the countrys electoral regulator earlier this year forced the yes effort to return a $23,450 donation from U.S. billionaire George Soros group, Open Societies Foundation. Ireland has a law against foreign spending on local political causes. But so far, the Standards in Public Office Commission has yet to ask the anti-abortion side to return any foreign donations or to stop the flow of help from foreign groups.

The indication is that there are huge amounts of money now being spent by the no side online, both by the official campaign but more significantly by people outside the country, OGorman said. Theyve done a huge amount of work over the years raising money in the U.S. Were looking at what we can do, and how we can scale up what were doing online, but we would never have that kind of money. Its just not going to happen, because we are generally much more transparent, accountable and open about our funding. We dont fundraise unethically, and that does put us at a disadvantage.

The Save the 8th campaign leading the anti-repeal effort in Ireland did not respond to a request for comment.

Steven Aden, general counsel for Americans United for Life, said U.S. activists are meddling in Irelands vote because the country is considered the crown jewel of the global anti-abortion movement.

We dont want to see Ireland go down the road of elective abortion like the United States has, Aden told me. Ireland is at the top of a very slippery slope, and were at the bottom, unfortunately. Were concerned this would accelerate a trend of imposing abortion-on-demand on unwilling nations in the name of womens health.

When I asked him how exactly AUL is involved in Irelands referendum and how much money its spending, Aden hesitated to answer. Theres not a lot I can tell you, he said. Most of it goes on behind the scenes. But were certainly encouraging our friends in the Irish Republic to vote wisely.

Offline, even three weeks before the vote, the referendum had a physical presence in Dublin. It was impossible to walk 20 feet here with encountering both a Vote Yes and a Vote No poster on every street corner, often stacked one on top of the other.