Donald Trump took a decades-long Republican consensus in favor of free trade and discarded it like the garbage that formed the backdrop of his economic address Tuesday.

That's one takeaway from Trump's big jobs and trade speech in western Pennsylvania. The presumptive Republican nominee went hard after Bill and Hillary Clinton without throwing fiscal conservatives who believe free trade is part of free markets, economic freedom and limited government a single bone.

At one point, Trump even quoted Clinton's Democratic primary opponent, socialist Sen. Bernie Sanders, as saying the former secretary of state "Voted for virtually every trade agreement that has cost the workers of this country millions of jobs."

Sanders is no small-government guy. But he has gotten Clinton to reverse herself for the Trans-Pacific Partnership, at least as currently constructed, and move away from her husband's default support from free trade.

That's just one reason many conservatives panned Trump's speech. While he was trying to sharply contrast himself with the presumptive Democratic nominee, some on the Right felt he was mimicking her instead.

"It was fitting that Donald Trump appeared to be standing in front of a mess of commingled recycled trash while he delivered his trade policy speech," wrote former Ted Cruz communications director Amanda Carpenter. "Because his plan appears mostly recycled from the platform of Hillary Clinton."

Yet the GOP consensus on trade can be exaggerated. There were pockets of conservative resistance to NAFTA and GATT during the 1990s. Three runners-up for the Republican presidential nomination who received strong conservative support — Pat Buchanan in 1996, Mike Huckabee in 2008 and Rick Santorum in 2012 — were to varying degrees protectionist on trade.

Much of Trump's Pennsylvania speech could have been lifted from Buchanan's 1998 book-length anti-trade polemic The Great Betrayal. Santorum attended and praised Trump's speech. Huckabee has emerged as a Trump defender.

Ross Perot, the last billionaire to make a serious run for the White House, campaigned against bad trade deals too. He wasn't a conservative or a Republican, but he siphoned millions of conservative votes in 1992 and 1996. Perot definitely leaned more to the right than the left.

The Republican Party was protectionist back when business was clamoring for trade protection. Even after the party began to champion free trade there was occasional backsliding, such as Ronald Reagan's support for trade restrictions to help Harley Davidson and American auto manufacturers and George W. Bush's advocacy of steel tariffs.

Even many conservative free traders tend to pivot by making national sovereignty arguments against the World Trade Organization or raising executive power objections over trade promotion authority.

Trump didn't delve much into this history, preferring to quote George Washington and Alexander Hamilton. Perhaps he likes musicals. But the businessman did talk about the older American economy, when tariffs coexisted with lower taxes at home.

"Our original Constitution did not even have an income tax. Instead, it had tariffs — emphasizing taxation of foreign, not domestic, production," he said. "Yet today, 240 years after the Revolution, we have turned things completely upside-down. We tax and regulate and restrict our companies to death, then we allow foreign countries that cheat to export their goods to us tax-free."

Economics aside, trade, like immigration, is an issue on which there is a sharp divergence between public sentiment and elite consensus. Nowhere is that sharper than among Republicans, where the party rank-and-file has quietly drifted in a protectionist direction while the party elites almost uniformly back free trade.

A poll commissioned this year by the Brookings Institution asked whether trade agreements were mostly helpful or harmful. Democrats were split on the question, with 49 percent picking harmful and 45 percent choosing helpful. Half of independents though trade agreements were "Mostly helpful because they open markets for U.S. companies and allow Americans to buy goods more cheaply," 43 percent disagreed.

Among Republicans, however, 60 percent said trade agreements were "Mostly harmful because they send jobs overseas and drive down wages." Only 35 percent thought they were mostly helpful. That split jumps to 69 percent harmful and 27 percent helpful when looking just at Trump supporters.

That jibes with a poll conducted by Caddell Associates, which found that 59 percent of Republicans believe trade deals mostly benefit other countries. Just 4 percent of Republicans said they mostly benefit the U.S., a third as many Democrats who said the same.

Look also at the exit polls from the primaries. In Mississippi, Republicans were actually more likely than Democrats to view trade as a net job killer. While 58 percent of the state's GOP voters said trade takes jobs while 34 percent said it creates them, Democrats narrowly picked creating jobs (43 percent) over taking them (41 percent).

Michigan Democrats were a bit more likely than Republicans to view trade as a net negative for jobs. Still, 55 percent of Republicans said trade takes away jobs, just barely behind the 57 percent of Democrats who said the same.

Even in Ohio, a state Trump lost, 54 percent of Republicans said trade takes jobs more than it creates them. (Trump barely beat John Kasich among these voters while he usually won them comfortably, a factor in his defeat.) That's one percentage point ahead of the 53 percent of Ohio Democrats who said the same.

Certainly, some of this reflects the fact that we are nearly eight years into a Democratic administration. Just as voters tend to trust presidents of their own party with more executive power in other contexts, like the war on terrorism, partisan loyalties also influence their confidence in a president's ability to competently negotiate trade deals. This explains why some Democrats are more sympathetic to free trade under President Obama — who promised to renegotiate NAFTA, like Trump, but then didn't — than many Republicans.

There is also a deep-seated nationalism among Republican voters, however, that can make them receptive to protectionist arguments. Despite his many policy reversals, Trump has expressed concern that foreign governments are cheating and disrespecting America for decades before it seemed likely he would enter politics. The occasional op-eds or blog posts he has signed touting outsourcing and even his own business practices notwithstanding, economic nationalism has been the one constant in Trump's politics.

Moreover, running against free trade during a year in which Sanders won millions of Democratic votes hitting Clinton on trade agreements could create the potential for crossover appeal. Trump may not be ideally situated to run against Clinton on ethics and transparency, but he's the only Republican who can credibly run against her past backing of the Iraq war and NAFTA. He is trying to win over Sanders voters, joining together the kinds of people who supported Perot, Buchanan and Jerry Brown for president in 1992.

Trump is unapologetically jettisoning long-entrenched GOP orthodoxy on trade but he may be taking the more popular position — even among Republicans.

There are, however, reasons to doubt Trump can pull this off. Globalization's losers are a much larger and more diverse constituency in the general election than the working-class whites drawn to an anti-globalism message in the Republican primaries. His sky-high negatives among black and Latino workers who might share his trade skepticism could limit how much of this vote he can tap into. Union members and the white liberals who voted for Sanders might be similarly reticent.

It's a problem that has plagued Republicans with a blue-collar conservative appeal in the past.

Another factor: Trump's speech and similar pronouncements on trade are likely to be rigorously fact-checked by both the mainstream media and liberal outlets. Few conservatives will defend him because they adamantly disagree with his policy conclusions.

Not all Republicans do, however, and Trump's only viable path to 270 in November runs through states where trade deals are a dirty word. So don't expect Trump to get on the same page as GOP free traders anytime soon.

Trump is leading an assault on the party's orthodoxy on trade and many Republicans are willing to follow.

Update: A previous version of this article reversed the Brookings Institute poll numbers on whether Democrats regarded trade as mostly helpful or harmful.