In the last few days, there’s been new talk about Paul Ryan in the who’s-in-who’s-out game of speculation over Mitt Romney’s vice presidential pick. The speculation is striking, because of the four candidates mentioned most often — Ryan, Rob Portman, Marco Rubio, and Tim Pawlenty — Ryan is the choice that would fundamentally change the direction of the Romney campaign. How? By instantly elevating the Ryan budget plan to the top of the Romney agenda. Whether that change would be to Romney’s liking is very much an open question.

There is an intense debate going on inside the Republican party over whether GOP candidates, focusing their campaigns on the economy, should stress job creation or reducing federal spending. The two aren’t mutually exclusive, of course, and Romney has embraced both, but there is no question Romney has emphasized job creation far, far more than any other issue.

Romney has also embraced Ryan’s economic plan. (Although if you read the Romney website, you’ll get the impression that it was Ryan who embraced Romney’s plan.) But look at Romney’s speeches and public pronouncements, as well as at his policy proposals. The heart of Ryan’s plan — controlling the terrifying growth of federal spending by transforming Medicare — isn’t at the heart of Romney’s agenda.

For example, look at “Mitt Romney’s Plan For A Stronger Middle Class: A Plan For More Jobs And More Take-Home Pay,” unveiled by Romney recently at campaign events in Colorado. The plan is based on five points, which Romney calls “Energy Independence,” “The Skills To Succeed,” “Trade That Works For America,” “Cut The Deficit,” and “Champion Small Business.” Under the “Cut The Deficit” heading are four sub-headings: “Immediately reduce non-security discretionary spending by five percent,” “Cap federal spending below twenty percent of the economy,” “Give states responsibility for programs that they can implement more effectively,” and “Consolidate agencies and align compensation of federal workers with their private-sector counterparts.”

Romney doesn’t emphasize overhauling Medicare in his stump speech, either. Creating jobs, getting the economy moving again — those are the points he hits over and over and over. Yes, Romney talks about bringing federal spending under control. But Ryan-like plans to curb entitlement spending? That’s just not something Romney emphasizes.

That would likely change if Romney picks Ryan. Should that happen, the Ryan plan would immediately become a far bigger part of the Romney campaign that it is now — it would, in fact, move to the top of the Romney agenda.

That’s something that unnerves a number of Republicans. They respect Ryan and the work he has done, but they worry that putting him on the presidential ticket would brand the Republican party as the party of austerity at a time when more voters are more concerned about job creation than budget cutting.

Of course, Democrats are going to bash Romney on spending cuts and Medicare reform regardless of what he does. Since that is inevitable, say Ryan supporters, why not put the plan’s most articulate defender, Paul Ryan himself, on the ticket? One reason would be that Mitt Romney has shown no inclination to make the Ryan plan the centerpiece of his campaign. Perhaps that’s what he’s planning — perhaps he planned all along to run on jobs until mid-August, only to pivot to entitlement reform for the rest of the campaign. But that’s not likely.