Rich Lowry‘s latest National Review Online column explains how Mott Romney’s Republican presidential campaign could benefit from adding House budget chairman Paul Ryan to the ticket.

Romney has to carry the argument to President Barack Obama. The state of the economy alone isn’t enough to convince people that Romney has better ideas to create jobs. Neither is his résumé. Romney needs to make the case for his program, and perhaps no one is better suited to contribute to this effort than Ryan.

Ryan is an ideologue in the best sense of the term. He is motivated by ideas and knows what he believes and why. But he’s not blinkered. He is an explainer and a persuader.

Before there was a House-passed Ryan budget, there was Ryan meeting with Republican freshmen, convincing them that true fiscal restraint was impossible without addressing entitlements. When the House passed his budget, there Ryan was plugging for it, as comfortable with Charlie Rose as Rush Limbaugh.

On top of fearing the Medicare issue, anxious Republicans worry that Romney will become too identified with House Republicans. But anyone looking at Ryan for two minutes will realize he runs completely counter to the stereotype of the wild-eyed House Republican. He is invariably civil, sure-footed, and good-natured.

Even with Ryan as veep, the presidential debate would not become all about the budget, as some nervous Republicans fear. The economy remains the biggest issue, and Ryan has always been clear that his budget is best understood as a tool of growth rather than an expression of austerity.