And "why it needs to be passed immediately if it will take years to work?" This is the weak spot politically
From the comments at the linked article:
“A lot of people quoted at this meeting do not seem very bright. Its simple economics that nobody seems to remember. To fix the economy you spend! You spend spend spend! Thats the whole point of this stimulus. Supply side economics failed during Reagan and they failed during Bush 2, Republicans need to understand this. This stimulus is trying to return us to Keynesian economics which has a proven track record and is really the only route to go. “