As far as arguments against a policy go, points like this are terrible: 

While some conservative Christians would like to see the rule [against religious organizations’ involvement in politics] abolished, others, especially the younger generation, support a clear separation of church and political endorsements. Many liberal churches are also active on policy issues, and could potentially get more involved in partisan politics.

Mayer noted that for some religious leaders, the IRS rule has given them a way to avoid political pressure for an endorsement.

“Now a church that wants to say no has an easy answer, it’s illegal,” Mayer said.

Really?  Those tasked with promoting and explaining a religion are timid about explaining why they might not want to endorse anybody, or even a particular candidate?  Nobody will be forced to express an opinion.  I suspect it’s more the truth that they don’t feel comfortable with it themselves and wish to restrain others from what they see as an unfair advantage.

Perhaps, too, those who object tend to be of the sort who are entirely on the same page as the secular culture, so they know their political work will get done, making it worth taking a slight hit in order to impede others whose Churches play a role to the secular culture.