First, he needs to express sympathy for the concerns of regular people, without actually being a regular person. Romney’s deficiencies in this area have been evident for months, but his stumbles continue. He jokes about job layoffs by his father. He moves forward with the renovation of his California dream home.

Yet the problem is revealed not just in the stumbles but also in strategy. In Wisconsin, Romney attacked Rick Santorum as a friend of “big labor.” This is an easy applause line in a Republican primary. But it is also the argument of upper management, just as Romney needs to begin appealing to the shop floor. Romney would help his cause by giving evidence of a political master plan beyond easy applause lines.

Romney’s second challenge is a persuasive defense of entitlement reform. A candidate not known for boldness has embraced Ryan’s bold approach to reforming Medicare and Medicaid. Now comes the assault. It is a perilous moment for the candidate and the Republican Party. If Romney is incapable of making the case on entitlements — or loses his nerve and tries to change the subject — it would be a devastating political setback. It would also, incidentally, be a devastating setback for the country, which is being hastened toward crisis by entitlement demagogues.

The very worst option for a Republican is the half-embrace of entitlement reform. A full, effective embrace by Romney would also provide a needed display of principle and passion. “You have to be a happy warrior,” says Ryan, “not ducking or fearing the fight.” Which may be the best argument for Ryan as Romney’s vice presidential pick.