Why is this difficult?
It does NOT say "Congress will tax subsidize such religion." Why is that so difficult? Do you understand the difference between taxation and speech?
Any church can say anything it wants. No one will be coming to take a preacher away for supporting a candidate or supporting law-breaking (although that breaks a different law). But there is nothing in that passage that says they get to be paid for that.
Let a church pay its taxes like everyone else and they can say anything they want (except for when they cross the truly unconstitutional McCain/Feingold crap). The only sanction is paying the taxes we all pay.
It says just the opposite actually.