The Obama-backed stimulus bill isn't really a stimulus. Yes, some of the money will stimulate the economy. Estimates on this vary partly because no one knows when the economy will recover. Once it does, this bill goes from stimulus to deficit spending. The Congressional Budget Office estimates that the economy will start to recover on its own by the end of the year. They also estimate that only a fraction of the stimulus will be spent this year so the vast majority cannot be called a stimulus. If you assume that the recession continues on into 2010 (making it several times longer than any previous recession) then there will still be at least 20% unspent.
There's a lot of money in the bill that could never be called a stimulus under any definition. There's $20 billion for Pell grants. This may be a worthy cause but it should be judged on its own. The vast sums set aside for green energy will not do much stimulus, either. If they ever pay off, it will be years in the future. Again, spending like this should be judged on its own merit.
I doubt that anyone in Congress really knows everything that is in the bill. It has been rushed through without hearings. The Democrats complained for years when the Bush administration did this with the Patriot Act.
That is the whole point of the bill. Democrats are anxious to start a new New Deal. They lumped everything that they could think of into a single bill and tried to sell it as an economic stimulus that was too urgent to be discussed. The public is becoming skeptical and is probably suffering from bail-out fatigue. Rasmussen says that only 42% of the public supports the bill. This highlights one of the reasons for the urgency. Democrats are worried that the bill cannot stand up to too much scrutiny.
If the bill becomes law then it will change daily life. Spending initiatives that are being sold as temporary will become permanent. That is why the Democrats are pushing the bill so hard.
At the same time, without Bush and his own big-government leanings, the Republicans have recovered some direction. The House Republicans were unanimous in voting against the bill. Even if it was a meaningless gesture, they are on record as being against this major expansion of government. Bipartisan support would have made it difficult to oppose unrestrained spending in the future.