What does ‘fiscal spit and glue’ mean?

Solution 1:

You've pretty much got it with "patchwork or a makeshift measure." A very similar usage of the phrase can be found in a 2008 article from Advertising Age: "Team McCain Reclaims Lead With 'Spit and Glue'". Reading that article might give you a clearer idea of the full meaning of the idiom. You can think of "spit and glue" as "whatever's at hand, though it might not be the ideal or preferred solution."

In the passage you quoted, the full phrase is actually "held together with spit and glue"--it's just confusing because "the fiscal equivalent" intrudes into the middle of the phrase. Something that's held together with spit and glue (or, as Kit mentioned, spit and baling wire) has been patched together to work for the short-term, but it's not very strong or stable, and may not last for long.