PALM BEACH, Fla. — Scott Walker likes to tell a story about shopping at Kohl's. Under instructions from his wife Tonette, Walker has learned how to pile on the discounts and coupons whenever he goes to the popular Wisconsin-based department store. If he sees a shirt on the rack with a tag that reads, "Was $29.99, Now $19.99," Walker explains, he goes to the cash register with a flyer from the newspaper and gets another 10 or 15 percent off. Then he pulls out his Kohl's credit card and there's another 10 percent. And another newspaper flyer that might be worth as much as 30 percent off. "And the next thing you know, they're paying me to buy that shirt!" Walker exclaims.

When Walker told the story at the Freedom Summit in Des Moines, Iowa, in late January, the audience ate it up — just loved it — and Walker was rewarded with rousing applause. Fast forward to Saturday morning, here in Palm Beach, when Walker told it again at a meeting of wealthy donors sponsored by the Club for Growth in an ornate ballroom at The Breakers, one of the most opulent hotels in America. The reception to Walker's story was polite, but noticeably more subdued than in Iowa.

"Probably not as many Kohl's shoppers here," Walker said dryly when I asked him afterward about the contrast. "In Iowa, the people went 'Yeah! We feel great when we get that 30 percent in the mail.'"

At The Breakers, in front of the contributors whose approval all GOP candidates hope to win, it wasn't quite the same. But Walker still saw value in telling the story. "A lot of these donors were frustrated after the last election because they were feeling … that Americans couldn't relate to our nominee," he told me. "So even if they don't necessarily relate to that story, I think they appreciate that someone like me can tell that story and relate to the people who we're going to need in the next election."

That's a huge part of Walker's appeal right now: He seems to be the Republican candidate who has the best chance of connecting with the millions of middle-class voters who have drifted away from the GOP in recent elections. And for that reason, Walker looks like the man who can attract almost everyone in the Republican camp — social, economic, and national security conservatives — in addition to those disaffected voters. That's a huge plus for Walker and, along with his impressive record in Wisconsin, is the reason he has shot to the first tier of the Republican race in recent weeks.

At the same time, Walker could be headed for trouble with the establishment, Washington-based wing of his party. Look for GOP insiders to begin whispering, and then saying out loud, that Walker needs to raise his game if he is going to play on the national stage. On the one hand, they'll have a point — Walker needs to come up with clear, crisply-expressed positions on a variety of national and international issues. On the other hand, Walker's way-outside-the-Beltway method of expressing himself might resonate with voters in primary and caucus states more than Washington thinks.

For example, in our conversation Saturday, I asked Walker what Republicans in Washington should do in the standoff over funding the Department of Homeland Security. "Not just Republicans, I think the Congress as a whole needs to find a way to fund homeland security going forward," Walker answered. He explained that he recognized the concerns lawmakers have about giving up their ability "to push back on the president's questionable, if not illegal, actions." Walker noted that he was part of the states' lawsuit against Obama's action. "I think they're right that the president is wrong," Walker told me, "but I also think we've got to make sure that homeland security isn't compromised."

After a little more along those lines, I said I was still a little unclear on where Walker stood. Should Republicans stand firm on not funding Obama's unilateral action on immigration, or should they go ahead and fund the Department of Homeland Security without regard to what Obama has done? Here is what Walker said:

I think they have to figure out some way to have the bridge to continue to fund homeland security but in a way that doesn't remove their ability to come back sometime in the not too distant future if the court rules or if the administration changes how they do this action in a way that could be upheld in court. They need to have the power of the purse string to offer a counter to that.

What does that mean, exactly? It's not entirely clear. On one hand, it appeared Walker was adopting the time-honored stance of the governor who stands outside the squabbling of both parties in Washington — a tactic that last worked quite well for George W. Bush in 2000. He'll appeal to more voters by not getting stuck in the Washington mud.

On the other hand, maybe Walker just hadn't thought it through very carefully. Certainly some parts of his performance before the Club for Growth led observers to suspect that he has not really dived into a number of big issues — not just foreign policy, but domestic as well — that will serve as tests for presidential candidates in coming months.

One easy question, at least as far as members of the Club were concerned, involved the Export-Import Bank. The Club wants to see it die; that's a good conservative position. All the other candidates who came to Palm Beach — Bush, Cruz, Rubio, Jindal — quickly and clearly said Ex-Im should be allowed to expire. But not Walker. Here's how he answered the question:

I think again, if you do what I mentioned with the tax code, if you make it fair and simple, if you do trade overall that's open and fair going forward across the world, across the globe, and you simplify the regulatory code, then the most compelling argument people would say is that this Bank is there because other countries have it, somehow we need it out there -- I think that's a faulty argument and premise, but I understand why today, when you've got all these other various regulations and a tax code that doesn't work and other things, but if you simplify the tax code, you simplify the regulatory climate, you pull back the frivolous and out-of-control lawsuits, there's no need to have it, and let the market drive everything, and those that are worthy of the competition, big or small, I think, will do well.

It wasn't exactly a straightforward answer, and the Club questioner noted that the audience would have liked to hear the word "eliminate." Walker eventually said he did not support re-authorizing Ex-Im, but it took a while to get there. In the end, Walker left the uncomfortable impression that he hadn't considered the question very seriously.

And then there was foreign policy. No one expects a governor to have dived deeply into international affairs this early in the race, but Walker is definitely a work in progress. In recent weeks, for example, he has cited his command of the Wisconsin National Guard as evidence of national security experience, and in Palm Beach on Saturday, he pointed to Ronald Reagan's 1981 firing of the air traffic controllers as "the most significant foreign policy decision of my lifetime" — a decision made, in case anyone missed the point, by "a president who was previously a governor."

Walker's comparison set off a lot of debate over whether the air traffic control firings, as consequential as they were, really supported the point Walker was trying to make. Whatever the case, Walker insisted that "Foreign policy is something that's not just about having a Ph.D or talking to Ph.Ds. It's about leadership." In our conversation, he said he has gathered together advisers — some of whom do have Ph.Ds — and is working on foreign policy questions.

Still, all that has led to some feelings of unease among policy experts and Republican insiders that Walker, for all his outward popularity, might be headed for difficulties over the substance of policy. Yes, he has a huge record of achievement as a governor. But will that be enough to get him through a long campaign?

In contrast, other Republican candidates — some with less impressive records of accomplishment than Walker — have shown a lot of fluency with national and international issues. From Jeb Bush, with his long exposure to both state and national governance, to Marco Rubio and Ted Cruz, senators who speak with some authority on big issues, to others like Bobby Jindal, and potentially John Kasich and Mike Pence, who have experience on both the state and federal stage — other candidates are ahead of Walker in their ability to come up with sharp and well-argued statements on domestic and foreign policy. Walker will have to reach beyond his record to compete with them on the issues and present himself to voters as a potential president.

It's not clear whether Walker's problem is temporary or longer lasting. Part of the difficulty is that he has found himself far ahead of where he thought he would be at this stage in the race, and is thus under a much hotter spotlight than he might have imagined. In our conversation, I asked whether the campaign had shifted under his feet. "Totally," Walker said, without a moment's hesitation.

"We thought all along if we got in, it would be kind of this slow and steady, don't worry about the other guys, just keep focused on moving forward, and as candidates chose not to get in or fell off, we'd be in a position to make a compelling case to them," Walker explained. "We had no idea that after that Iowa summit there would be that kind of acceleration to the race. But we're here, and we're not going to complain about it."

Walker assumed that in the best-case scenario he would be in for a long, slow move to the front of the Republican pack. But he caught a slingshot out of Iowa and instead finds himself at the top of many GOP lists at a very early point in the race. Now he has to take some time to catch up with himself.