Bernie wants to convince voters that Biden is a traitor on “fair trade.” Photo: Chip Somodevilla/Getty Images

Joe Biden is campaigning as an old-school labor liberal — one who’s uniquely qualified to win back disaffected Obama-to-Trump voters in the Midwest. Since launching his candidacy last week, the Democratic front-runner has collected endorsements from major unions and seen a bump in the polls — one fueled, in no small part, by Democratic voters’ faith in his “electability.”

Biden is also a longtime champion of NAFTA, the Trans-Pacific Partnership, and China’s admission into the World Trade Organization. The Democratic Party pursued all three of those trade policies over the near-unanimous opposition of organized labor — a point that Donald Trump took pains to emphasize when campaigning against Clintonism in 2016. In fact, the Republican nominee effectively used NAFTA as shorthand for the Democrats’ purported betrayal of its traditional working-class base. And those attacks, combined with his demagogic messaging on immigration, helped to reduce the salience of class resentment in the 2016 election, and send a critical mass of midwestern Obama voters into the GOP coalition.

Thus, it makes sense that Bernie Sanders is already focusing his fire on Biden’s “fair trade” bona fides. Casting the Democratic front-runner as a serial betrayer of industrial workers doesn’t just undermine Biden’s standing with a key interest group in the primary, but also challenges his claim to electability — which, polls show, is the No. 1 quality that Democratic voters are seeking in their standard-bearer this cycle.

Shortly after Biden launched his campaign at a union hall in Western Pennsylvania this week, Sanders went on CNN and assailed his rival’s views on trade. “When people take a look at my record versus Vice-President Biden’s record, I helped lead the fight against NAFTA; he voted for NAFTA,” Sanders said. “I helped lead the fight against [permanent normal trade relations] with China; he voted for it. I strongly opposed the Trans-Pacific Partnership; he supported it.” The Vermont senator proceeded to release a video spotlighting this point, and a news release calling on his fellow Democratic candidates to embrace his trade agenda. When Biden suggested Wednesday that China was not a serious competitor to the United States, economically or geopolitically, Sanders immediately fired back, tweeting, “Since the China trade deal I voted against, America has lost over 3 million manufacturing jobs. It’s wrong to pretend that China isn’t one of our major economic competitors. When we are in the White House we will win that competition by fixing our trade policies.”

I am proud to be the only candidate running for president who not only voted against NAFTA and PNTR with China, but also stood on the picket lines with union workers opposing these unfair trade deals. pic.twitter.com/KfTsOtzWZq — Bernie Sanders (@BernieSanders) April 30, 2019

Sanders is hardly alone in seeing trade as Biden’s Achilles’ heel. As Politico notes, a wide variety of progressive activists and organizations, including some aligned with Elizabeth Warren’s campaign, are mounting a similar line of attack.

“There are many reasons Joe Biden is the least electable Democrat our side could possibly nominate,” said Adam Green, the co-founder of Progressive Change Campaign Committee, which supports Elizabeth Warren. “Being seen as cozy with big corporations and loving to cut backroom deals with political insiders are two of those reasons — and they are exactly what trade deals like the TPP represent. That’s the opposite of the outsider zeitgeist Trump tapped into in 2016 and will try to repeat in 2020.”

This argument appears sound enough on the merits. In current polling, Biden does look like the strongest Democratic candidate against Trump, not least because of his relatively high support among whites without college degrees. But it is true that he boasts the very same trade record — and cozy relations with financial-industry titans — that Trump used to mitigate the Democrats’ advantage among economically liberal, working-class voters.

What’s more, if history is any guide, no one wants to run as a champion of the existing trade system in a Democratic presidential primary, especially those who support said system. In 2008, Obama assailed NAFTA as “devastating” and a “big mistake.” In 2016, Hillary Clinton disavowed Obama’s TPP, a trade deal she had previously hailed as “the gold standard in trade agreements.” Ostensibly, Clinton and Obama did not adopt these positions for kicks, but rather, for electoral advantage.

But this time might be different. As the Republican Party’s standard-bearer has claimed the mantle of protectionism, negative partisanship has led a significant number of Democrats to embrace the opposite view. In 2009, 34 percent of Democratic voters told Pew Research that free-trade agreements had “generally been a bad thing for this country”; last year, that figure fell to 19 percent.

Photo: Pew Research Center

Meanwhile, Trump’s tariffs have spurred a backlash in several midwestern states, where agricultural interests have lost more from the president’s policies than industrial workers have gained. It’s possible that these trends will reduce the potency of anti-NAFTA arguments in the Democratic primary, while the same Obama nostalgia that’s propelling Biden’s candidacy will take the bite out of attacks on the TPP.

That said, it’s quite possible that Democratic voters will be responsive to a critique of Biden’s trade record on electability grounds, even if they aren’t on substantive ones. Surveys suggest a large majority of Democrats are looking for the candidate who’d be most likely to defeat Trump, not the one who best represents their own views. If Sanders can convince these voters that Biden’s support of NAFTA makes him a less-than-ideal general-election candidate, then they may start viewing Uncle Joe’s other betrayals of core Democratic constituencies — from consumers to African-Americans to feminists to retirees — in a less forgiving light.