By "spending money", I suppose you are referring to sales tax?
Sales tax is collected at the state level, not the federal level (where the transfer payments primarily occur). Buying groceries does not contribute toward the vast majority of housing assistance, TANF, Medicaid, or any federal assistance programs. Only ~25% of transfer payments occur at the state level, and states themselves (on average) receive ~33% of those funds from the federal system. (IOW, the average state receives money from the feds to the tune of ~330$ billion).
Those receiving housing assistance and food assistance are not even contributing as much as has been mentioned. The NIH reports ~25% of illegal immigrants are elderly or near-elderly, which means they will never contribute what they cost. Additionally, ~16% are children, meaning although they may contribute in the future, they will not do so now.
Simply increasing the population does not increase the federal tax base at all.
Increasing the tax rate is precisely the sort of question I was asking; but who do you want taxed more? The top 1% pay 42% of all federal taxes already, and the top 10% pay more the entire bottom 90% combined. AND this still results in a enormous deteriorating primary deficit.
As things are right now, excluding illegal immigrants, very large spending cuts or tax increases are already necessary. How do you propose to pay for more?