The Antle/Spencer “Give them their earmarks in exchange for slashing everything else” argument seems premised on a surprisingly naive understanding of the workings of Congress. Consider the defense of pork that Daniel Patrick Moynihan used to make. The idea is that the earmarked goodies are okay because they buy political support for more important legislation.
Pointing out that pork is only a small part of the budget misses the point. The best conservative/libertarian case against pork is embedded right in Moynihan’s moderate/liberal case for it: It’s the pork that greases the skids to pass those big, expensive bills. Theoretically, pork could also also be used to build a majority for budget-cutting legislation, but that’s usually not the way it works.
Earmark reform throws up a roadblock to passing major legislation, and as Phil reminds us below, legislative roadblocks that make it harder to cut entitlement spending also make it harder to massively increase it. Given the tendencies of our political class, that’s a trade-off that Leviathan-wranglers should be pretty happy with.