What's the big idea, Chris Christie?

But Mr. Christie’s bigger problem with a conservative primary electorate won’t be his words; it will be what he’s describing with them. His warm-up presidential speeches have been vague—heavy on personality and the need for “leadership” and “renewal.” This is partly a function of early days in a presidential campaign, but it’s also a tacit acknowledgment that Mr. Christie’s policy record—by comparison with some other would-be GOP contenders—is relatively thin.

He pushed through a modest 2011 pension reform, though he has since acknowledged it wasn’t enough by proposing round two. He managed a property-tax cap, though he gave up on his bolder plan to cut income-tax rates by 10%. New Jersey looks better under Mr. Christie, but it’s still a big-tax, big-regulation place. Wisconsin Gov. Scott Walker —who has accomplished more in his own left-leaning state—will have fun pointing this out.

Mr. Christie’s impulse may be to spend time justifying his record and blaming his Democratic legislature, though that won’t help with his “leadership” theme. His best shot is therefore to look forward and wow conservatives with a full-throated economic and tax-reform agenda—especially since nobody has much of an idea what a Christie agenda would encompass. His policy proposals to date have been Jersey-specific, and narrowly tailored to that state’s political realities. What GOP voters in Iowa, New Hampshire and elsewhere want to know is what’s “big” in Mr. Christie’s mind when it comes to federal tax policy, entitlements, health care and foreign policy.