David Frum has
an idea:

Beyond that why isn’t he yelling his head off about the Republican default threat? Why isn’t he being specific about what it could mean? And why isn’t he doing what Lyndon Johnson would do – making it clear that if H-Hour does arrive, he’ll use disbursement power just as politically as Republicans are using the power of the debt ceiling: eg, paying Medicaid bills from Blue states first, Red states later? Paying farmers and other Republican constituencies with IOUs, while hoarding cash for Democratic voters?

Works for me.