From a Friday Washington Post article:
Casting his appeal in religious terms, Bush said, "We must meet our moral obligation to treat newcomers with decency and show compassion to the vulnerable and exploited, because we're called to answer both the demands of justice and the call for mercy."
He added, "Most Americans agree on these principles. And now it's time for our elected leaders in Congress to act.... Each day our nation fails to act, the problem only grows worse. I will continue to work closely with members of both parties, to get past our differences, and pass a bill I can sign this year."
NPR's All Things Considered echoed this the same evening: "The president told the Prayer Breakfast that each day the nation fails to act on immigration, the problem only grows worse, and Mr. Bush used religious terms as he appeal to lawmakers.... [']We must meet our moral obligation to treat newcomers with decency and show compassion to the vulnerable and exploited, because we're called to answer both the demands of justice and the call for mercy. Most Americans agree on these principles — excuse me — and now, it's time for our elected leaders in Congress to act.[']"
Is it really quite accurate to describe this as "us[ing] religious terms"? I would think that nonreligious people would rightly bristle at the implication "moral," "decency," "compassion," "justice," or "mercy" are inherently "religious terms."
The full transcript, if you want it, is here. I didn't see any expressly religious language in the immigration passage, though there are references to God and prayer elsewhere in the speech (it was, after all, given at a prayer breakfast).
UPDATE: Some commenters suggest that all these terms are in context religious terms because they were used at a Prayer Breakfast. But both items already mentioned that this was said at a prayer breakfast; the "religious terms" seems to me to suggest that there was something more explicit about the terms' religiosity (or about the immigration passage more broadly).
On the other hand, some others suggested that "called to" was the religious term, and the "religious terms" was a way of suggesting this. Maybe that explains it, but I'm still skeptical; the passage still strikes me as being the sort of thing that could have been said at an agnostics' convention as easily as at a prayer breakfast, and as the sort of thing that would have pretty much the same meaning at both. Of course, there might be subtle differences in the resonances the terms have based on the audiences' religious beliefs, but pretty subtle, much as "do not kill" -- a far more morally uncontroversial assertion, I realize -- would have different resonances but only subtly different ones when said to a Christian group as when said to an agnostic group.