The surprise news that Pope Benedict XVI will abdicate the papacy at the end of the month got us to thinking about a topic we wrote about quite a bit in the run-up to the 2012 election: the Catholic vote.

As we noted during the fall, the Catholic vote has long mirrored the overall national presidential vote. And, it happened again on Nov. 6, 2012.

President Obama carried Catholics 50 percent to 48 percent while he won the overall national vote 51 percent to 47 percent. That's the third straight election where the Catholic vote has been a near-carbon copy of the overall vote.  In 2008, Obama carried Catholics by nine points and beat Arizona Sen. John McCain (R) by seven points nationally. Four years earlier, George W. Bush won the Catholic vote by five points and beat Massachusetts Sen. John Kerry (D) by three points nationwide.

Here's a look at how closely the two votes have tracked over time, according to exit polling:

The 2012 result also marked the fifth time in the last six presidential elections where the candidate who won the Catholic vote has won the election. The lone exception was in 2000 when then Vice President Al Gore won the Catholic vote by two points (and the popular vote by .5 percent) but lost the presidency to Bush in the electoral college.

It's worth noting, however, that Catholics comprised just one in four voters last November -- the lowest percentage of the overall electorate for the group in the past six presidential elections. And, of course, trends are only true until they aren't anymore -- meaning that if in 2016 the Catholic vote goes for the eventual loser the theory of Catholics as the swing vote could go out the window.

One other fascinating element to the Catholic vote: It's changing as more and more Latinos -- a heavily Catholic voting bloc -- become a bigger portion of the overall electorate.  The strength of Democrats among Latinos --President Obama won 71 percent of them in 2012 -- is helping the Catholic vote move more Democratic.

Still, that the Catholic vote running so closely aligned to the overall national vote for such a long time is certainly worthy of note.