You may consider it settled,as may many experts,I do not consider it settled.The state cannot tell the people how to worship and the state cannot tell the people that they cannot vote or serve if they are not of a certain faith.The constitution does not say that the church(which is a collective expression of the people) cannot use the state to advance their agenda up to the point that they are using the state to force others to worship(or not) in a certain way.I cannot see a pastor saying the GOP _or the democrats) is the party most in line with God's will as a threat to democracy in and of itself.I do not see it as a threat to the church.