?
Not much. A Christian Democrat is usually "socially moderate" and takes a more decentralized approach to welfare programs, typically prioritizing the state, local, or neighborhood church level. Assuming the country is in such bad shape that a party has collapsed there's probably some consensus around bigger government to solve those problems. Most of you have probably heard of Social Democracy but Christian Democracy is an idea that hasn't really come to the Anglosphere yet.
I come from the Italosphere, so I am pretty used to the idea of Christian Democracy. At the same time I know that it is not really part of the Anglosphere. Indeed what animated my questions is that I don't really see much space for Christian Democracy in the American Democratic Party.