Comment by andsoitis

While the 3 minors are US citizens, their parents are not and the parents can be deported because they are in the country illegally.

That means you have the following options:

a) deport nobody, i.e. you don't apply the law

b) deport just the parents. What do you do with the minor children? Separating them from their parents (different countries) would be cruel.

c) deport the entire family, including the US minors. Since they have US citizenship, they can always return to the US.