Well: he needs to given his own view of religion in politics. Here's the president's citation from Jefferson in his speech at Monticello on July 4:

In one of the final letters of his life, he wrote, "May it be to the world, what I believe it will be -- to some parts sooner, to others later, but finally to all -- the Signal of arousing men to burst the chains, and to assume the blessings and security of self-government."

Here's the original:

May it be to the world, what I believe it will be, (to some parts sooner, to others later, but finally to all,) the signal of arousing men to burst the chains under which monkish ignorance and superstition had persuaded them to bind themselves, and to assume the blessings and security of self-government.