"Small business and Bush tax cuts are 2 separate bill," he said. "It [estate tax fix] won't go on the small business because that's just too big."
The idea behind the combination is that the current marginal rate cuts for the wealthy are unlikely to be a part of legislation extending the Bush tax breaks. Adding an estate tax fix to the bill provides richer taxpayers with at least some relief since they are the ones most likely to incur a tax on their estate.
Baucus did not say when the Bush/estate tax bill would move, but hopes to markup the small business tax bill next week.