I agree. Their purpose is fairly obvious. It's to use the deficit/debt argument to dismantle the welfare state. Doesn't matter if it holds water.
Spending on Republican objectives is fine.
Indeed, raising insufficient taxes to pay for Republican objectives is fine. This is where they pretend "supply side" growth will cover the deficiency. A claim for which there is no evidence. Famously used by Paul Ryan to make his nonsense budget balance.
They invent multipliers when it suits them and ignore them when it doesn't. Either dumb or dishonest. Not sure which.