It's not a matter of _keeping_ government subsidized public mail, because that does not really exist right now. I read "let's keep USPS state owned / public" as

It's not a matter of _keeping_ government subsidized public mail, because that does not really exist right now. I read "let's keep USPS state owned / public" as suggesting that the existing relationship between the USPS and the US government (a largely self-funding independent agency) should be kept as-is, but that the postal monopoly should be broken up.