"Nearly two months after the Sept. 11 attacks, with the United States tumbling into recession, Congress and the White House remain mired in partisan wrangling over a package of tax cuts and spending increases to revive economic growth.</br></br>Analysts now warn that if the political stalemate continues past Thanksgiving, the lack of a fiscal ""stimulus"" package would deepen the recession and render the eventual recovery less robust while sending stock prices tumbling again on Wall Street.</br></br>""If we're going to limit the severity of a recession, we need to quickly nip this in the bud,"" said Princeton University economist Alan S. Blinder, a former vice chairman of the Federal Reserve. ""Otherwise, you get a set of dynamics where one layoff leads to another, and the economy can spiral down rather quickly.""</br></br>Economic forecasters differ on how much a package of additional tax cuts and spending increases would boost an economy now weakening faster than most had expected, but all agree it would help.</br></br>At the most optimistic end, Macroeconomic Advisers of St. Louis calculates that every dollar in additional spending and tax cuts will add $1.50 to economic output over the next 18 months. If another $90 billion in stimulus is added to actions already taken -- roughly the amount in both House and Senate packages -- the U.S. gross domestic product should grow by 3.2 percent next year, up from current projections of a 1.6 percent growth rate without, according to economist Chris Varvares."