What is the central conflict in "The Outcasts of Poker Flat"?

The central conflict in the short story revolves around the outcasts, who are escorted to the edge of town and warned not to return.  The town has decided to purify itself of undesirables, people who are a prostitute, the Duchess, a gambler, John Oakhurst, Mother Shipton who is a madam, the woman who is in charge of the prostitutes, and Uncle Billy a drunk.

After these four are expelled from Poker Flat, they encounter on the road out of town two innocent young people, Tom Simson and Piney Woods, the two young people are running away to elope.

The combination of the four undesirables and the two innocents makes for an interesting story.  The dynamic that develops with the addition of the two young people to the group of four changes the outcasts into people of character.

These four people were thrown out of town because they were considered unworthy by the townspeople, because of their habits or occupations, after they meet Tom and Piney, they redeem themselves through their sacrifices on behalf of others.

Except, maybe Uncle Billy, who steals a mule.  But Mother Shipton gives up her food share to help keep Piney nourished, John Oakhurst, sacrifices himself, but before he does, he collects firewood to help keep the women in the cabin warm.  After Mother Shipton dies from lack of food, the Duchess takes on the motherly role, protecting Piney, huddling with her to try to keep her warm.  In fact when the rescue party arrives, they find the two women huddled together, frozen to death.