Over and over again, public opinion polls have showed Hillary Clinton ahead with Catholic voters. Like everything else in this topsy-turvy election, however, that trend is less clear than it seems, and may have shifted in recent days.

Historically, whoever wins the Catholic vote wins the presidency. It’s seen as a key bellwether, even if the Catholic vote itself is not monolithic.

Practicing Catholics tend to hold more socially conservative views than the general population, while non-practicing Catholics tend to hold more socially liberal views. Still, the overall Catholic vote is seen as predictive, and most polls that showed a cross-tab for Catholics have shown Clinton ahead.

A PRRI poll, for instance, made headlines this week for showing Clinton with a commanding 11 point lead among Catholic voters.

By such a wide margin, some might be ready to call the election a few days early. But like everything else in this year’s election cycle, it won’t be that easy.

As he often is, the devil is in the details.

Released on Halloween, the PRRI results were aggregated from a series of four polls held between Sept. 22 and Oct. 17. Only a fraction of the four aggregated PRRI surveys would have included the fallout from the firestorm generated by the Wikileaks’ revelation about emails Clinton campaign staff sent regarding Catholics.

In one set of those emails, top Clinton staffers made comments that many saw as offensive about Catholics. In another set of emails, Clinton’s campaign chair – John Podesta – discussed using political operatives to advocate for doctrinal change from within the Church.

In addition, none of the PRRI polling included the possible effect of the FBI’s recent announcement about its continued investigation of Clinton-related emails. The snapshot taken by PRRI simply ended before the Clinton campaign had faced its late-October surprise.

Now, one top daily tracking poll is consistently putting Trump ahead among Catholics – often by double digits. As of Nov. 2, it had Trump ahead of Clinton among Catholics by 13 percentage points – 50 percent to 37 percent.

The poll making this claim is not some obscure or partisan operation, but the IBD/TIPP daily tracking poll – rated by Nate Silver as the most accurate national poll of the last presidential cycle in 2012.

In short, the most recent data on Catholics from one top-rated poll suggests that Trump, not Clinton, is solidly ahead with Catholic voters, obviously conflicting with the results of other surveys.

There are a couple of possible scenarios.

It is possible that the other polls were right, and that this poll is wrong.

It is also possible that the other polls were right, and this poll is right too, capturing a more recent snapshot after a couple of important developments for Catholics.

Of course, methodological errors are possible, and the sample size of the new survey is fairly small, but the consistency of Trump’s lead in this daily tracking poll suggests at least the possibility that some sort of shift among Catholics may be happening.

With less than a week to go, we’ll have to wait until the ballots are cast and counted to know for sure.