So people educated with public funds but without kids will allocate 0$ to education, then complain that youths these days just hang in the street doing no good, and allocate more of their tax towards policing?
And the default, if someone doesn't choose any categories, would go to some proportion that Congress would decide. However, allowing even a "small" portion - which could still be billions of dollars - to be allocated directly by taxpayers would gather some very interesting data.
It would be very interesting to see which agencies would attract the most money, and what strategies they'd use to attract people to give their discretionary tax dollars to them.
Would people give more to the CDC, NIH, NASA, the Dept of Housing, Dept of Transportation, Dept of Homeland Security, ... ? We could start to get a direct temperature of what is ailing people the most and what they want their money to fund.
Government agencies could even "advertise," or at least try to get positive news articles that really highlight what they're accomplishing, to spread the word about the good they're doing. It could engage people more in exactly how their money is being spent, and care further about government, because they have at least a small hand in directly funding different departments.
At a used bookstore, I found a book(1) about Marian Franz that illuminated the history behind their attempts.
Weirdly enough, there was a personal dedication in the front by David Gross(2), one her colleagues and someone who wrote extensively about the 'War Tax Resistance'.
I'm not religious, so it kinda made me sad, but that book sent me down a rabbit hole. Could you live on 20k a year to avoid income tax and contributing to a war effort? Its impressive.
(1) https://www.goodreads.com/book/show/6553714-a-persistent-voi...
(2) https://www.theatlantic.com/business/archive/2014/11/can-qui...
I lived for quite a while in Kansas, where the state constitution makes adequate funding of schools mandatory. The result is a never-ending series of lawsuits in which the legislature claims to have provided adequate funding, and a court finds that they haven't and orders them to increase or redistribute the funding (sometimes it's found that they under-funded the schools overall, sometimes it's found that they distributed the funding in ways which result in some districts not having adequate support).
This and a few other back-and-forth fights led to the former governor and his party-aligned state legislature attempting to change the selection process for judges, and attaching a rider to that law which would completely defund the state court system if the courts ruled they didn't have the authority to change the selection process, and hinted that if they still ruled against him he'd attempt to recall the entire state supreme court and replace them with partisans who'd support him.
In my mind part of the job of elected politicians is to ensure that tax money is spent where their platform said it would.