If Republicans win the White House in 2016, they probably won't have a filibuster-proof majority in the Senate. Most of the Senate seats up for election next year favor Democrats.
That could stop the Republican agenda dead in its tracks.
If that happens, says Jonathan Chait, Republicans will kill the 60-vote filibuster rule in the Senate. That's the only way they could implement big parts of their agenda, including any roll back of Obamacare and deregulation of the financial industry.
The filibuster could not stop the entire Republican agenda. Parts of the Republican program could be passed through budget reconciliation, which allows changes to taxes and spending to pass with a majority vote. Republicans could pass big upper-bracket tax cuts, and reductions in Medicaid, food stamps, the Earned Income Tax Credit, housing vouchers, tax credits for health insurance, and other good stuff that forms the core of the Ryan budget.
But important elements of the Republican agenda could not be passed through reconciliation, because they involve regulations, not just taxes and spending.