My friend Andrew Malcolm gleefully needles the White House by pointing out that the results of a massive Gallup survey of 275,000 Americans shows that Muslims give Barack Obama the highest job approval rating, but that’s actually been the case all along.  That number has dropped eight points since Obama took office, however, and that trend is seen in every faith demographic in the survey — even among atheists.  In every other category, Obama has dropped by double digits since the first six months of his presidency:

Muslim Americans continue to give President Barack Obama the highest job approval rating of any major religious group in the U.S., while Mormons give the president the lowest ratings.

The differences in Obama’s approval ratings across the religious groups included in this analysis have held fairly constant across time, even as Obama’s overall rating has fallen by 15 points between the first half of 2009 and the first seven months of this year. American Muslims — in the news recently with the controversy over proposed plans to build an Islamic center and mosque near ground zero in New York City — have given Obama his highest ratings in all three time periods: 86% in the first half of 2009, 83% in the second half of 2009, and 78% so far this year. Mormons have given Obama his lowest ratings across time, dropping from 43% in the first half of 2009 to 24% this year.

In addition to Muslims, Obama receives above-average ratings among Jews, those who identify with other non-Christian religious groups, and those with no formal religious identity. Obama gets lower-than-average ratings among Protestants. Catholics have given Obama slightly higher-than-average ratings last year and so far this year.

Those numbers shouldn’t be news for a Democratic President.  His original support levels were in line with historical trends among these groups simply on party affiliation.  A 77% approval rating among Jewish voters for a Democrat is about what one would expect to see from voting patterns.  On the other hand, a drop to 61% indicates big trouble.  If Obama loses that much of the Jewish vote in 2012 or discourages that much of it in the upcoming midterms, he will find himself in deep trouble — and that’s assuming it doesn’t get any worse.

Likewise, the same is true for the Christian denominations.  The Protestant bloc is highly influential, and Obama has dropped 15 points in a year to 43% among them.  Catholics, a more natural constituency for Democrats for reasons that frustrate this particular Catholic, have gone from 67% approval to 50%, the second-largest drop (Mormon approval dropped 19 points to 24%).  Even atheists have lost faith somewhat, dropping 12 points to 63%.

Lately, we have begun to hear pushback on the use of approval ratings to gauge electability and political strength.  The argument goes that some of the bleeding is coming from the Left, which is unhappy but highly unlikely to vote Republican, and it’s true to some extent.  However, unhappy voters don’t contribute money to campaigns, don’t organize, don’t do phone banking, and often don’t bother to vote at all.  Others vote for the alternative.

Earlier this week, a couple of polls about how voters perceive Obama’s religious inclinations created a deluge of teeth-gnashing and garment-rending from the media.  The real story may be that people of almost all faiths have begun serious reconsideration of Obama, and that this will cause some problems if he expects to run for another term of office.