Bernie Sanders has been making waves this week, and not in a good way.

On Thursday, the Vermont senator held a rally in Omaha, Nebraska for mayoral candidate Heath Mello – a Democrat personally opposed to abortion rights. The event, which included the Democratic National Committee’s deputy chair Keith Ellison as well, was part of a larger DNC-hosted series dubbed the ‘unity tour.’

As The New York Times noted, this title was anything but apropos:

An Omaha mayoral election on May 9 may seem an unlikely place for this fight to play out, but a collision was inevitable. Despite being the most sought-after Democrat in the country today, Mr. Sanders is actually an independent and self-described democratic socialist animated chiefly by class uplift. But the clamor for his attention comes as the party is increasingly defined by its positions on issues related to race, gender and sexuality.

Sanders shows no signs of remorse:

Sanders pushed back against the criticism. “The truth is that in some conservative states there will be candidates that are popular candidates who may not agree with me on every issue. I understand it. That’s what politics is about,” Sanders told NPR.

“If we are going to protect a woman’s right to choose, at the end of the day we’re going to need Democratic control over the House and the Senate, and state governments all over this nation,” he said. “And we have got to appreciate where people come from, and do our best to fight for the pro-choice agenda. But I think you just can’t exclude people who disagree with us on one issue.”

In my view, this internecine Democratic controversy gets at the heart of an issue that not nearly enough Bernie supporters (among whom I include myself) have grappled with. In the immediate aftermath of the election, there was much handwringing on the Bernie-supporting left about how he would have fared in a general election matchup against Donald Trump.

Far less discussed was the more important question of how he would have fared as president if he had won. I have always liked the idea of Bernie, but the reality of a Sanders presidency is one I’ve barely considered: much like a Trump administration, it seemed too far-fetched to consider.

But in the wake of this recent flareup, it’s worth evaluating Bernie Sanders’ usefulness to the progressive movement. In a way, he got lucky in that his longtime single-minded obsession with economic inequality was particularly well-attuned to a post-Occupy Wall Street America. His nothing-if-not-consistent drumbeat about the disproportionate gains of the top 1% amplified the disparate strands of anti-neoliberalist activism into a cohesive movement. This is no small feat.

And so, perhaps because ‘economic anxiety’ is now the watchword of post-2016 Democratic strategy, Sanders’ reputation as a by-the-books progressive has endured notably well, especially given the residual bitterness felt by many Hillary supporters (whose ranks I eventually joined) due to Bernie’s blistering critiques of Hillary as a puppet of Wall Street.

What we are seeing now, then, is something a little closer to reality: Bernie helped formulate the new Democratic mainstream on economics, but his skillful appropriation of an emboldened economic left masked his increasing heterodoxy on issues like gun control and, we now know, reproductive rights.

Now that abortion rights are clearly under assault by a Trump administration that just placed a probable Antonin Scalia clone in the ninth seat of the Supreme Court, Bernie’s willingness to shrug off a core tenet of the Democratic Party is no longer ignorable.

Indeed, there is something highly ironic about Bernie Sanders – whose entire primary campaign against Hillary could have been summed up, not entirely sans justification, with the question ‘What’s the point of a Democratic Party if you don’t take a stand on the important issues?’ – advocating compromise on one of the most fundamental battles animating the progressive base in 2017.

In a large sense, Bernie – who himself is not a Democrat, a point he explicitly reiterated on Tuesday – has decisively won the war for the heart and soul of the Democratic Party in the wake of Hillary’s defeat to a crude populist. But his implicit message of ideological purity goes only as far as the issue he cares most about: economic inequality. All else is negotiable. But he may be in for a surprise, if the newly emboldened left starts feeling similarly about him.