It starts with Toby and Sam and Josh, being brilliant goofballs, as usual, picking on C.J.-as-straightman, as usual.
One of the primary plots of the episode is C.J.'s struggle to take on the ritual obligations of the Thanksgiving holiday that are visited upon the White House, which she comes to really enjoy, despite her own resistance.
Another plot consists the discovery in a storage container of a large number of refugees from China, who claimed to have fled their home to escape religious persecution.
As is always the case with Sorkin, he brings all these plots together, throwing out all sorts of short random scenes which serve to hammer home the merged themes of the episode. Which, in this case, is that America is a wonderful place, whose every action reflects its complicated, sometimes ugly, but always (on one level or another) glorious history, and which remains, in the end, a blessed land to which all those who love God and/or freedom will want to come.
Great Thanksgiving propaganda, and great television. And kind of a great story too.