Perhaps the biggest of the big lies is that the government will not be able to pay what it owes on the national debt, creating a danger of default. Tax money keeps coming into the Treasury during the shutdown, and it vastly exceeds the interest that has to be paid on the national debt.
I'm not a bankruptcy lawyer, so I don't know whether creditors would consider a country to be in default if it paid interest on its loans, but reneged on promises to its citizens for things like Medicare and Social Security.
What I do know, is that if the American government kept paying Chairman Mao his usury, while cutting off Grandma's health care, then that government would be finished. Putting rich commies ahead of poor seniors is about the surest form of political suicide I can imagine.