CNN had an article cover these exact questions. The summary is that taxes will not be raised. Democrats want to keep the economy good so they can make a run for the white house in 2008. So don’t expect any drastic change. In the past, when you have opposite parties in the legislative and executive branches economy tend to do very well, especially the stock market. Just like the Republican control of the legislative when Clinton was in power. The reason economy do well in this condition is that no major laws will come out since they will veto each other. Wall Street loves it when there’s no major shock.
