I've often wondered what the result would be if budgets were determined by something like that.
Just the line items of potential things to spend money on, and citizens indicating their preferences, without any emotive rhetoric to color their choices.
Since my personal discussions with people end up with a lot of agreement on how much one should be allocating to things like education, R&D, infrastructure and healthcare, but it all seems to go pear shaped when it reaches the voting floor, due to the large role external, non-voting actors can play in shaping those decisions.
I don't want a hundred million here and there to go to rubbish projects as a sop to a politician with a certain amount of influence who just received a donation to add an extension to his house.
Of course, now you have the problem of how things end up on the list to vote on :)