This is not going to hurt Ford. As a matter of fact it may help him.
The Ford Family Memphis Mafia will make sure that Shelby County will turn out in huge numbers for Junior. What he did, or didn't do won't matter to them, anyways.
However, He needs to win over Tennessee's middle ground if he wants to win statewide. And this will certainly hurt him with them, not because he went to a Playboy party, but because he went clintonian with his denials.
It puts the lie to the "pious Jr" fraud that he's been working overtime to pitch to the "crackers."
People who were already disposed to vote for him will probably be more convinced to vote for him. Social conservatives who bought into his pious Christian fraud will be thinking twice. He's not only a libertine, he's a hypocritical liar. To some people honesty still matters.