Whether an organization is participating or intervening, directly or indirectly, in any political campaign on behalf of or in opposition to any candidate for public office depends upon all of the facts and circumstances of each case. For example, certain "voter education" activities, including preparation and distribution of certain voter guides, conducted in a non-partisan manner may not constitute prohibited political activities under section 501(c)(3) of the Code. Other so-called "voter education" activities may be proscribed by the statute. Rev. Rul. 78-248, 1978-1 C.B. 154, contrasts several situations illustrating when an organization that publishes a compilation of candidate positions or voting records has or has not engaged in prohibited political activities based on whether the questionnaire used to solicit candidate positions or the voters guide itself shows a bias or preference in content or structure with respect to the views of a particular candidate. See also Rev. Rul. 80-282, 1980-2 C.B. 178, amplifying Rev. Rul. 78-248 regarding the timing and distribution of voter education materials.
As stated, depends upon all of the facts and circumstances of each case. It would remain to be seen if petition instructions would stand the test of "voter education" or if there was a "bias or preference".
However, neither exempts any sermon from being subpoenaed as part of discovery to defend the lawsuit brought against the City of Houston. Just like the alternate discussion in this thread about First Amendment and tax exempt status, these are two different thing.