Thanks for clarifying. This paper present a fairly coherent view of the nuances behind that question, I think.
The answer to your question is not obvious, which is presumably at least part of the reason that NASA funding has languished so badly in recent decades. It has a broad base of support (~80%), but the general public has a surprisingly poor understanding of that agency's size and scope. People overestimate its share of funding to a huge degree (a nontrivial percentage think it takes up half of federal spending!), and consequently think we spend too much; it's not clear what would happen if the majority of the population actually found out how little we actually spend on the problem, as they would in an election that prioritized NASA as an 'issue'. It's a bit like a candidate with low familiarity among the voter base, in that it's generally seen as an opportunity to 'frame' the message more completely.
Well, I doubt I'm representative of US voters, but to my mind NASA suffers primarily from not having a realistic medium-term mission that anyone (beyond science geeks) cares about and from being a bloated, sclerotic, and highly inefficient government organization. Neither problem can be fixed by more funding.
"The White House Office of Science and Technology Policy is planning ahead — way ahead. The agency wants you to email ideas for how "the Administration, the private sector, philanthropists, the research community and storytellers" can develop "massless" space exploration and a robust civilization beyond Earth."
This is beautiful.
"We are running out of adventures [...] the mountains have all been climbed, the continents explored, and the romance of sailing away on a tall ship to undiscovered islands is no more. What will fire the imaginations of the next generation?"
http://io9.com/white-house-seeks-advice-on-bootstrapping-a-solar-syst-1647619795