We know and they know it's against the Society's rules, but they call it a "conscience matter" for legal reasons. Here's an example of why they do so, from the state of New Jersey:
19:34-29. Obstructing or interfering with voter
No person shall by abduction, duress or any forcible or fraudulent device or contrivance whatever, impede, prevent or otherwise interfere with the free exercise of the elective franchise by any voter; or compel, induce or prevail upon any voter either to vote or refrain from voting at any election, or to vote or refrain from voting for any particular person or persons at any election.
As usual their lawyers are on duty, making sure the publications remind you of what your conscience is supposed to tell you to do, without putting the rules in writing. "Plausible deniability".