(CNN)In case you needed a reminder that President Barack Obama isn't running for office again, he just alienated not only Republicans, who have largely resented him from day one, but the progressive base of Democratic voters. Obama has argued with the progressive potentate Elizabeth Warren, calling her "wrong" on trade policy.  The Massachusetts senator is the same potentate to whom Hillary Clinton has been religiously prostrating.  What everyone does next will be critical for the 2016 elections and the future of Democratic politics. Warren has publicly criticized so-called "fast track" trade authority that would allow the White House to negotiate massive, multination trade deals with little congressional oversight.  The authority would pave the way for trade pacts such as the Trans-Pacific Partnership, which is modeled on the North American Free Trade Agreement, and has killed 700,000 American jobs and drove wages down in the United States while simultaneously decimating Mexican agriculture and small businesses. Aspects of the TPP deal would provide incentives for off-shoring jobs to low-wage countries, imposing limits on government regulations around food safety and the environment, and create mechanisms for multinational corporations to challenge any domestic laws they simply don't like. In December, Warren wrote a letter signed by several other Democrats to U.S. Trade Representative Michael Froman raising concerns about the TPP.  The letter warned that the TPP could erode safeguards that have been put in place to "prevent future financial crises." "We cannot afford a trade deal that undermines the government's ability to protect the American economy," Warren wrote. At a town hall with MSNBC's Chris Matthews on Tuesday, President Obama said, "I love Elizabeth. We're allies on a whole host of issues. But she's wrong on this." Obama added, "When you hear folks make a lot of suggestions about how bad this trade deal is, when you dig into the facts, they are wrong." But "I'm right and she's wrong" doesn't exactly come off as a thoughtful, let alone respectful, response to the policy critiques of one of the most trusted economic justice leaders in the Democratic Party today. Meanwhile, Hillary Clinton is trying to walk a fine line somewhere in the middle.  Clinton has recently courted Warren's support while forcefully repeating the rhetoric of populism. But according to a report by The New York Times, Clinton's staff is at pains to suggest that Clinton has always been a populist as opposed to merely trying to now co-opt a current trend.  Yet it becomes harder to paint Clinton as the "original Elizabeth Warren" each time she equivocates on trade policy and the TPP. In a 2012 speech as secretary of state, Clinton praised the TPP as "the gold standard in trade agreements to open free, transparent, fair trade, the kind of environment that has the rule of law and a level playing field." But now, as she campaigns for president facing a Democratic electorate divided over the deal, Clinton is sounding more critical. "Any trade deal has to produce jobs and raise wages and increase prosperity and protect our security," Clinton said this week. So does Clinton support the TPP deal or not? Campaigning in New Hampshire on Tuesday, Clinton reportedly declined to say one way or the other.  That's not the behavior of a fierce populist.  It's more indicative of the sort of politically calculated, ideologically centrist "triangulation" for which her husband was famous. Seizing on Clinton's ambiguity, her potential challenger in the Democratic primary, Martin O'Malley, released a video this week making clear that he is against the TPP. According to a poll, as of 2012 just 1 in 4 Americans believed that NAFTA had benefited U.S. workers and only 1 in 3 believed it had benefited the U.S. economy overall. Even most Republicans in this poll supported the position that the United States should either "renegotiate" or "leave" NAFTA versus "continue to be a member." In other words, any political leader with even the dimmest grasp of economics let alone political pragmatism should run away from a new trade deal modeled on imitating and expanding NAFTA.  While it's not surprising that Republicans are siding with big business and against working Americans in supporting the TPP, it's befuddling that President Obama supports it. The only hope now is for 2016 Democratic candidates, especially Clinton at this point, to support populism not just in rhetoric but in real policy terms and show which party is, for the most part, on the side of the people and not on the side of multinational corporations. Senate Majority Leader Harry Reid minced no words in revealing his position about trade "fast track" authority: "I'm not only no, I'm hell no." If Hillary Clinton wants to prove she's a real populist, now's her chance to be even more clear.
Sen. Elizabeth Warren has publicly criticized so-called "fast track" trade authority .
Sally Kohn: Why does President Obama call her wrong, and why is Hillary Clinton equivocating?