Every time the federal government goes to the markets to borrow money to pay for deficits in Medicare, this is money that will not be producing a cash benefit. Every time we fulfill our national obligation to help out our fellow citizens who are hurt by natural disasters, this is money that is not going to flow into U.S. coffers.
And yet, these are expenditures we must make. Medicare is a hugely important obligation to which millions of people have contributed in the belief that it will be there for them when they reach 65 years of age. The federal government has an obligation to insure that these people get the benefit of this arrangement. Similarly, we cannot turn our back on Americans ravaged by hurricanes and earthquakes who are suffering through no fault of their own. To do so would just be wrong. The federal government must therefore make investments that will produce the revenues needed to pay for our societal safety net.
Yet, in our current environment, this is never going to happen. So successful are the Republicans at selling the story that all debt is bad, and so weak have the Democrats been in their response to this false narrative, that we now find that Democrats are actually treating the Republican pitch as if it were gospel.
Why?

Because you liberal dickhead, we are broke and can't afford all this crap anymore.  We don't have the money...we don't have the money...we can't pay for healthcare for everyone over 65, we can't and should never have promised to, we can't let people live near the sea, in storm paths and pay when their homes are wrecked as if that is not predicitable.

We can't afford all this crap anymore...don't you get it?

There is no bad debt, there is no good debt, you idiot, there is debt and we are spending our childrens, childrens money.  We are broke.