Claiming and un-claiming in politics

People have wishes and desires, that's natural.

Politicians change wishes and desires to claims, inciting thus the energy to work or to fight for them.

Liberal and left politicians change claims to "just claims"; which means that the desires are to be satisfied out of justice. (Conservative politicians do the same, sometimes, but not so often.)

There are a lot of concepts of justice, some rather acceptable, some more puzzling. That's in particular the problem with our ideas about a "just distribution of goods". Is it to be (a) equal distribution or (b) unequal distribution according to the persons' (subjective? objective?) needs or (c) unequal distribution according to the persons' efforts (achievements? efforts? mere energies given into their work, even if unfruitfully)?
Then, what's about supporting particular persons (which gives them an advantage they wouldn't have had otherwise)? Is it justifiable in all cases? Do parents have a right to save money (or buy property) and to let it over to their children? Or should property be confiscated after death? Is supporting particular persons allowed if these persons are disadvantaged beforehand (like, your child is crippled). Can we decide by objective criteria which persons are enough disadvantaged to allow us to give them particular support?

In average politics, politicians simply pick and choose that particular concept of justice which is apt to justify their particular claim today. (Tomorrow, with other claims they may refer to a contradictory concept.)
That is made possible because people tend to think (or simply pretend) that justice is a matter of intuition. "Every good man would FEEL that OUR claim is a just one - and if you don't feel so, you show us that you are not a good man." That's an effective way to avoid any discussion about the justice of a party's claims.

From a Christian point of view, men have first to un-claim, to lay down their claims, before they can start a discussion in whose end they may be find a common concept of justice. Also, from a Christian point of view, a lot of wishes and desires can be satisfied out of grace, without referring to a concept of justice at all.

But will liberal Christians really try to tell that to liberal politicians?