You will notice that one of the first links on the USCCB page is to a doctrinal note from the Vatican on the issues of voting from 2002.
The CAF guide supposedly uses this document, but then truncates the list of moral principles which Rome has declared “that do not admit of exception, compromise or derogation”. For example, an obligation to oppose “modern forms of slavery”, “Peace”, and to the development of an economy “with respect for social Justice” are all dropped.
Further, some prinicples, like “Analogously, the family needs to be safeguarded and promoted, based on monogamous marriage between a man and a woman, and protected in its unity and stability in the face of modern laws on divorce: in no way can other forms of cohabitation be placed on the same level as marriage, nor can they receive legal recognition as such” are severely abridged (in this case, solely to gay marriage).
When asked several years ago about the guide, the Church discouraged its use. A task force was formed and now there is a prohibition, universally supported by the USCCB’s pro-life committe, which would seem to preclude the guides use altogether (primarily on the basis that it is partisan, not theological. Again, you can read more about this at the USCCB’s web site.