Republican presidential nominee Donald Trump has made protecting American jobs from outsourcing one of the focal points of his campaign. Not everyone on his campaign agrees.

Stephen Moore, a fellow at the Heritage Foundation, is one of the 13 men who Trump announced earlier this month would be his top economic advisers. Moore is a former longtime Wall Street Journal columnist and former president of the Club for Growth, a conservative PAC. He's championed the free-market, supply-side economics that were once the hallmark of Republican politics.

Trump, in contrast, is a vocal opponent of free trade, calling NAFTA a "disaster" and the Trans-Pacific Partnership "a rape of our country."

Last year, Moore and CNBC commentator Larry Kudlow penned an article in the conservative National Review assailing Trump's protectionism, which they dubbed his "Trump Fortress America platform."

"He clearly sees international trade and immigration as negative-sum games for American workers," they wrote, describing both immigration and free trade as "prosperity building blocks" and Trump's proposed tariffs as "worrisome in the extreme."

They asserted that despite some misgivings, NAFTA is "a great success" and tariffs on Chinese imports would "hurt America at least as much as Beijing."

"Free trade is also vital to American jobs" and "also the greatest antidote to poverty and deprivation in the world's history," they added.

Moore justified this apparent contradiction in a blog post.

"Hillary Clinton flip-flops every day on free trade, so why is it that only Trump would cause a recession?" he wrote Tuesday. "Meanwhile, Trump is calling for the biggest tax cuts and reforms since Reagan. He supports massive regulatory relief and school choice. Trump wants to kill Obamacare. On energy, Trump wants a pro-America drilling policy. Clinton wants to soak the rich, increase the debt, stop energy development, expand entitlements and double down on Obamacare. How is this a difficult choice for a free marketeer?"

For his part, Kudlow, now also a vocal Trump supporter, still describes himself as "part of that fetish" of free trade, but justified Trump's other economic bona fides.

"He has a very good corporate tax-cut plan, across the board, for large companies and small companies," Kudlow told Breitbart News' Stephen Bannon, now Trump's campaign CEO, in March. "He's got a 15 percent rate--we're about 35 to 40 percent now." Lowering the tax rate would galvanize "tremendous movement of capital and labor back to the United States," he added.

While Kudlow has changed his mind about Trump, he remains firmly against tariffs, which he still argues will hurt American consumers.