OK, beyond not being to point to anywhere that any formal "religious test" exists, this writer needs to "do the math."
I believe LDS doesn't have all that many more voters in the U.S. than say, Muslims. So say a Muslim runs for POTUS.
There's no "test" for Muslim candidates, either. Still, such a candidate would need to convince Christian voters that when his faith labels such Christian voters as "infidels," somehow he is not part of that infidel-labeling faith.
Likewise, any LDS candidate needs to convince Christian voters than when his faith labels all Christian voters as "apostates," somehow he is not part of that apostate-labeling faith.
Likewise, any LDS candidate needs to convince Christian voters than when his faith labels all Christian voters as “apostates,” somehow he is not part of that apostate-labeling faith.
Your average Mormon has stronger adherence to the traditional Judeo-Christian values than your average secularized non-churchgoing American, as the Mormon sect (or ‘cult’ as you call it) is an American offshoot sect from Christianity.
Thus, when Romney stands up for families and supports the Family Marriage Amendment, has concerns about Obama pushing sex ed in early grades, points out that out-of-wedlock births are a problem, joins with pro-life Americans in opposing abortion on demand, he does so within the framework of shared Judeo-Christian values.
A Muslim is outside that faith tradition entirely.