It really depends on what approach he takes later in the game.
Mormons seem to have two extreme options when it comes to their faith in politics.
The first is
JFK's approach. At the time Catholicism had a similar status to Mormonism today so I do think the two cases are analogous. JFK confronted voters fears and mistrust head on while also emphasising that there should be absolute separation of church and state and a rejection of religious tests. He asked people to judge him on his record, not his faith.
The second is Romney's.
Fred Clark outlined this brilliantly in the last election. Romney had given a very high profile speech that basically insisted that it was faith that mattered, and he hated atheists just as much as the evangelicals did.
Romney's gambit here comes straight from the school yard. As a Mormon, he is an outsider, getting picked on by the bullies of the religious right. Instead of standing up to the bullies, he sucks up to them, trying to prove his loyalty and win their approval by acting like them and picking on the other outcasts and outsiders. "You guys want to pretend that 'secular' and 'profane' are synonyms? I can do that. Look, I'll even beat up this atheist kid for you. See? I'm just like you guys!"
This desperate, canine obsequiousness infuses his sniveling speech with fearfulness and flopsweat. Romney is pleading, begging to be allowed to serve as the bullies' toady. As far as that goes, he has probably succeeded. Eager-to-please toadies can come in handy, so the bullies will probably be willing to accept him in that capacity.
But as useful as they may sometimes be, toadies are never liked, respected or admired by the bullies. Nobody likes or respects or admires an unprincipled coward. And the characteristics of a successful toady don't fit with anybody's notion of the characteristics of a potential president. A toady can't get elected president (the best he can hope for is a Connecticut senate seat).
He was arguing for a message that only appeals to people who would use that very argument to disqualify him from the presidency.
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As for the early presidents/found fathers being deists, I'd go more with the
theistic rationalist view of them. The definition can get a bit nit-picky, but in general a theist prays and a deist doesn't.