At this point it is unclear whether the Republicans seeking to block the changes have the ability to get it done. If the bill is presented as a stand-alone piece of legislation, then it might be easy for President Obama to veto it unless a lot of Democrats in Congress get behind the bill.
However, Republicans might attempt to add this to another piece of legislation, such as a spending measure, that would be more difficult to veto. As of now, they are not certain what they will do.
Of course, the prospects for this bill and anything else having to do with the estate tax could change dramatically after the elections in November if either party scores a big victory.
