It is hard to overstate the risks Romney is taking in making a choice that virtually guarantees a far-reaching debate about the broader role of government and the entitlement state. Simply put, it is a debate Republicans have almost never won when they’ve put it directly before voters in the past.

As Newt Gingrich learned when he squared off against Bill Clinton in the 1990s, and George W. Bush learned with his politically disastrous efforts at Social Security reform in his second term, voters may despise spending and deficits in the abstract but they like many of these programs in the particular…

“Going big has risks, but fewer than going small,” a top Romney adviser told POLITICO early Saturday, after news of the decision broke. “Now this is a race about what the future’s going to look like. … This was all Mitt’s decision. These are two guys who love data, and have a similar way of looking at the world. … Mitt isn’t thinking about Ohio or the Hispanic vote. He’s thinking: ‘I’m gonna be president. Who’s going to help me succeed?’”…

Perhaps so, but Romney and his aides have a lot of questions to answer: If being ready to govern on Day One was the chief criteria, how did Romney, who has scant foreign policy and national security experience himself, overcome the objection that his vice president would have even less? If the basis of Romney’s campaign is that he is a business-minded Washington outsider, what attracted him to someone like Ryan, who has been in Washington since his twenties and has no business or executive experience?