"Stimulus" Will Lead To Permanent Government Expansion
A more rational analysis is provided here by Jim Manzi. Even though the proposed stimulus package is supposed to address the current cyclical slump, only a small part of the increase in spending will actually be implemented in 2009, and with nearly half being implemented after 2010. A much higher proportion of the tax cuts will be immediately implemented, with almost nothing remaining after 2010. And at that time the Bush tax cuts will expire, meaning that significant tax increases will come then.
And as Manzi points out, the risk is high that once the supposedly temporary spending programs are in place, supporters of them will argue that by extending them they're not increasing spending, they're avoiding cuts, something which will increase the likelihood that an even greater proportion of the spending increase will remain after 2010, making it in effect permanent. There are precedents for this, including how the reason the United States has farm subsidies is that the government wanted to provide "temporary" relief for farmers during the Depression of the 1930s. That "temporary" program however is still in place.