Avik Roy explains that repealing Obamacare via the reconciliation process wouldn’t be difficult for a Republican president with Republican majorities in both houses of Congress. All that would be needed would be a repeal bill that strategically left in some of the spending cuts contained in Obamacare in order to make the overall repeal measure deficit-neutral. 

What that means is that Republicans would only need 50 votes in the Senate to repeal Obamacare, instead of the usual 60 required to overcome a filibuster. That is to say that repeal is a likelihood if Republicans are able to capture the Senate along with the presidency in 2012. As Roy notes, even Mitt Romney, who is otherwise the biggest question mark on health care in the Republican primary, has committed to repealing Obamacare using reconciliation.