I'm not sure where these numbers are coming from. Sole proprietors file Schedule C on their personal returns, and S Corporation taxes are passed through to individual owners' returns, as well. That implies they should be paying the same rate; there is no separate S Corporation tax rate. If Obama (with Congress) cuts taxes on 95% of Americans, i.e. people making less than $200K per year, then they'll also be cutting taxes on the vast majority of subchapter-S corporations and sole proprietors.
Also of potential interest on this topic, the effect of changes in the Marginal Tax Rate on small business formation in the United States:
Also of potential interest on this topic, the effect of changes in the Marginal Tax Rate on small business formation in the United States:
http://www.aarongreenspan.com/filing/mtr.pdf