I must admit, I have always accepted, agreed, that churches should not be venues for political opinions. I based this on the fact that they enjoy a tax-exempt position.
On the other hand, I believe that governments do not have the right to withhold any portion of an employer's income.
In essence, the IRS should be abolished. This country needs to adopt another, more equitable way, of supporting it's governing bodies, both federal and state. If churches are included in this support, so be it. They are free then, without question, to comment on the political scene.
Besides the entire form of taxation (income) of our current system, your response to me made me wonder about how our current tax code treats political parties. I don't think they pay any kind of income taxes on contributions.