The WSJ's Steven Waldman writes today that "to a degree rarely seen" both McCain and Obama are weighing the religion factor in their VP choice.

On McCain, Waldman says:

John McCain is now earning less support from white evangelicals - by about eight percentage points - than George Bush had at this point in the campaign. While they're avoiding McCain, they haven't yet signed on with Obama. So, McCain can, and must, get some of those evangelicals back. He's also in a tough battle with Obama over Catholic voters, again doing a bit worse than Bush had.

And on Obama, he argues:

Obama is trying to get moderate and liberal evangelicals to switch sides. More important, he is trying to win centrist Catholics, and appears to be doing a bit better with that group than John Kerry had. That's why quite a number of his rumored VP picks are Catholic.

Waldman analyzes how the most-mentioned VP candidates helps each nominee with the religion factor. Read the whole thing.