If advocating the cause of the poor is a legitimate function of the magistrate, then taxation for that purpose would also be legitimate. The state has no other way to fund it's obligations.
I do agree that the magistrate could ask the churches to help. But if the Christian population is too small, then that won't help much.
I'm trying to drive this back to what the magistrate is obligated to do, when people in his domain are afflicted by poverty, not because of laziness but because of genuine hardships (famines, recessions, disease, etc.).
If he's suppose to preserve life (6th commandment), doesn't that include ensuring his people don't die of starvation, just as much as it does protecting them from murderers?
