Donald Trump may be blowing up Republican politics as we know it, but his most lasting impact may be more substantive — he has pushed the GOP into a much more populist corner on policy, challenging the party’s platform on everything from free trade to entitlements.

Trump’s populist positions on Wall Street (“Hedge fund managers are getting away with murder”), free trade (“We need fair trade, not free trade”) and immigration (“We’ll have a great wall”) are resonating at a time when conservatives are openly grappling with how to reach working- and middle-class voters when the GOP platform best reflects The Wall Street Journal editorial page. 

“We have to develop policy ideas that deal directly with their concerns,” said longtime GOP pollster and strategist Glen Bolger.

John Brabender, political strategist to former Sen. Rick Santorum who sought unsuccessfully to appeal to working class voters in his presidential campaign, said GOP elites who covered their eyes eight months ago are paying attention to Trump now. 

“They didn’t want to believe it,” Brabender said. “For the establishment, familiarity doesn’t breed contempt. It breeds comfort.”

Trump diverges from GOP orthodoxy in significant ways: While Republican elites push to rein in or privatize entitlements almost as a matter of faith, he vows to preserve Medicare and Social Security — while reassuring that “we're going to take care of the people on the street dying” after he repeals Obamacare.

Trump is strongly protectionist on trade and pushes closed borders to reassure workers who feel threatened by undocumented workers and the exodus of manufacturing jobs. 

He proposes even more massive tax cuts than his Republican rivals, but casts his tax plan as a way to lift up middle-class families and stick it to Wall Street.

And on top of all that, he boasts that he can’t be bought by the special interests and advocacy groups that normally fund political campaigns. 

But if Trump’s success in New Hampshire has forced the GOP establishment to recognize it has a problem, neither conservative elites, nor reformers are rushing to embrace prescriptions that they see as underdeveloped, far-fetched and, in some cases, mean-spirited. They argue his success has been fueled by his persona, not his positions.

“Obviously Trump has tapped into an anger felt throughout the country, and voters have good reason to be angry at Washington,” said Doug Heye, a former spokesman for the Republican National Committee and a sharp Trump critic. “But that anger isn't exclusive to any particular demographic and should demand serious policy prescriptions. Which Trump eschews.”

Here’s how he stands on six big issues, and how those stances have helped him consolidate support among blue-collar voters.

Immigration

Perhaps no issue has galvanized Trump’s supporters as much as his bellicose posture on immigration. Besides his push to build a wall on the border with Mexico, and his demand that Mexicans pay for it Trump has suggested rounding up and deporting 11 million undocumented immigrants. He also wants the birthright citizenship of their children revoked.

While those ideas resonate with stressed voters who lost ground in the Great Recession and who see immigrants as competitors and even as freeloaders, they rankle reform conservatives as well as traditional business-minded Republicans.

“The idea of building a wall just absolutely runs counter to the free market business ideals that you would think a businessman could wrap his head around,” says Craig Regelbrugge, a lobbyist for the horticulture industry.

Michael Strain, an economist at the American Enterprise Institute.

Strain, said that presidents like Ronald Reagan have courted voters with similar fears without being so divisive. “We’ve seen presidents who have been able to do that but who haven’t been morally offensive and unserious,” he said.

Trump’s also railed against temporary work visas, which he says hurt American workers. But Republican strategists worry that stance alienates Hispanic voters when the party seeks to broaden its base by appealing to both blue-collar workers and Hispanics. 

Trade

Trump has called for as much as a 45 percent tariff on Chinese exports to the U.S. and a 35 percent tax on cars crossing the Mexico border, arguing his protectionist approach would bring high-paying manufacturing jobs back to the U.S.

“We’re going to beat all of these countries that are taking so much of our money away from us on a daily basis,” Trump said at his New Hampshire victory speech on Tuesday. “It’s not going to happen anymore.”

He has also called out corporations like Apple, demanding they “build their damn computers and things in this country.” He boasts of “a great relationship with the unions,” and labor leaders worry Trump’s message could appeal to their members.

“He targets people like us. But what is he really pushing?” said Richard Trumka, president of the AFL-CIO. Trumka has blasted Trump, who opposes raising the minimum wage, for "a campaign fueled by contempt and exclusion."

While Trump’s plan for high tariffs might appeal to workers worried their jobs are disappearing overseas, trade experts say his proposals would actually hurt his blue-collar base by raising the price of cheap imported goods.

Trump’s position “is out of whack with the Republican party four years ago,” said Derek Scissors, a China expert at the American Enterprise Institute. “The question is how far out of whack is it with the Republican Party now?”

Entitlements

While Trump has denounced Obamacare, he’s also spoken approvingly of single-payer systems in the past, making it difficult to figure out his precise positions.

Trump has vowed to oppose cuts to Social Security and Medicare and to ensure every American has health coverage, horrifying some on the right. “It was a red flag for me,” radio host Rush Limbaugh said last week about Trump’s promise not to leave anyone without access to needed care.

Unlike Republican ideologues he doesn’t want to reduce the size of government so much as make it competent from his perspective.

Policy analysts compare his platform to that of European populist parties, which have a more nativist appeal, vow to protect the safety net and put less of an emphasis on the social issues that have animated many conservatives in the U.S. for decades.

Trump also supports allowing Medicare to negotiate drug prices with pharmaceutical companies — a longstanding Democratic idea reflexively opposed by the GOP. But the idea may resonate with a public fed up with skyrocketing drug costs.

“Who better than Donald Trump to be your chief negotiator with the drug companies?” said Dean Clancy, a veteran GOP health wonk backing Sen. Ted Cruz.

Taxes

Like other GOP candidates, Trump proposes a massive tax cut that would benefit the top 1 percent more than middle-class — making it hard to believe, as Trump claims, that he’d pay more under his own plan. (Trump appears to be the only Republican candidate to have once backed the “wealth tax” popularized by the French economist Thomas Piketty.)

There are a few populist pieces to Trump’s plan. Under his proposal, the number of taxpayers who won’t owe income taxes — Mitt Romney’s famous 47 percent — would jump to 63 percent, according to the Urban-Brookings Tax Policy Center.

But Trump has also been more willing to play up his man-of-the-people bona fides than some of his rivals.

During a recent GOP debate, Gov. Chris Christie of New Jersey called raising taxes on the wealthy “class warfare,” even though polls shows the idea is popular. In contrast, Trump often plugs his proposal to end the preferential treatment of carried interest that help private equity managers. And he isn’t shy about dumping on the Wall Street types who actually aren’t the prime beneficiaries of carried interest. “The hedge fund guys didn’t build this country,” he said last August.

Education

Trump’s anti-Common Core, pro-school choice positions are in line with the GOP and he’s open to scrapping the Education Department. But Trump also sounds like liberal hero Sen. Elizabeth Warren when he talks about college loan debt. 

“These student loans are probably one of the only things that the government shouldn’t make money from and yet it does,” Trump wrote in his 2015 book “Crippled America.”

That line could resonate with voters across the political spectrum. Polling has found that a strong majority of Republicans, Democrats and independents believe that college loan debt is a major problem.

Defense/National security

Trump reassures voters fearful of terrorist attacks and America’s place in the world with his calls for a military “so big and so strong and so great” that he says no one will mess with it. He’s called for destroying the Islamic State, without saying how, and plugs his opposition to the 2003 Iraq invasion. 

He’s also talked about barring Muslims from entering the country. And most recently, he defended waterboarding, going further than his rivals by saying he’d “bring back a hell of a lot worse than waterboarding.”

At the same time, Trump has shown minimal understanding of some key foreign policy issues, once suggesting he got his advice on security matters from the Sunday shows. He’s confused the Kurds with the Quds Force, and been unable to explain the nuclear triad — gaps that have not eaten into his support so far.

And while he’s called China and Mexico trade bullies, Trump has praised Russian President Vladimir Putin, who has become a pariah among other Republicans.

At a Dec. 15 debate, Trump said he would seek to block the Islamic State from using the Internet, even as he offered no details. "ISIS is using the Internet better than we are using the Internet and it was our idea," he said, adding he would "get our brilliant people from Silicon Valley” to solve the problem.