3% for scientists is just as bad as 3% for the military (although military defense is a constitutional duty of the federal government while funding research is not).
I argue that 3% of GDP is a ridiculous amount to give to 480,000 scientists. How many research projects that get grants actually benefit society? How are many esoteric studies of useless phenomena?
Does the taxpayer profit from fruits of the research the taxpayer funds? Nope. Any federally funded research should result in patents in the public domain that are open to all.
Given that we don't have the basics such as universal health care, pensions, or a social safety net that comes any where close to that in the EU, I think the money is better spent somewhere other than science at this time.