WASHINGTON — Normally, members of Congress would have no problem working together to protect houses of worship from having to pay taxes, especially in an election year when both parties want to earn the faith community’s vote. But in an era of pervasive partisan politics, not even that is a guarantee. Some Republicans do want to tweak a portion of their 2017 tax bill that will now force nonprofits, including churches, to pay a 21 percent tax on the value of certain employee benefits.