Can a Christian be a county clerk in the United States?

Short post here: The argument presented here is that being a Christian is incompatible with government policy and the implication is that Christian government officials must be afforded special powers non Christians are denied, for example, the power to substitute personal religious beliefs for official public policy. This injects religion into not only the function of government employees but the electoral process as well. Voters would rightly want to know which variety of candidate was seeking their vote.

The problem, of course, is that it's unconstitutional on its face.

Article VI. The Senators and Representatives before mentioned, and the members of the several state legislatures, and all executive and judicial officers, both of the United States and of the several states, shall be bound by oath or affirmation, to support this Constitution; but no religious test shall ever be required as a qualification to any office or public trust under the United States. (emphasis added)