Last week I became the Chair of The Sanders Institute (TSI), an initiative that grew out of the Bernie Sanders presidential campaign of 2016. While as a sitting senator, Sanders cannot be involved in the work of TSI, we are committed to elevating the issues on which he based his run for the White House.

TSI’s purpose, as defined in our mission statement, is to revitalize our democracy by fostering an informed electorate and advocating progressive ideas through civil discourse. The foundation of TSI’s effort will be built on a collection of remarkable founding fellows who will provide leadership on a range of economic, environmental, racial and social justice, and foreign policy concerns. They include such distinguished scholars and activists as: Harry Belafonte and Danny Glover; Robert Reich, Stephanie Kelton, Cornel West, and Jeffery Sachs; Bill McKibben, Ben Jealous and Michael Lighty; Tulsi Gabbard and Nina Turner; and Jane O’Meara Sanders, whose idea it was to launch TSI.

Of the matters we discussed at our first board meeting, what struck me as central to our mission was a collective commitment to civil discourse. Recent events have brought home just how vital it is to focus on changing the way we debate and challenging those who use personal attacks, harsh tactics, or vulgar language in an effort to stifle opposing points of view.

During last year’s presidential contest, Americans across the partisan divide were shocked by language and antics of then-candidate Donald Trump. He demeaned his opponents; defamed vulnerable minority communities; courted and emboldened extremist groups; and sometimes even incited his followers to violence.

There were those who hoped that once taking the oath of office Trump would change, but the language he uses in his daily tweets and off-the-cuff remarks at press events demonstrate that those hopes were in vain. As a result, there is clear evidence of a frightful coarsening of our discourse and an empowering of hate groups.

Our concern, however, is not limited to what Trump has done because we are seeing worrisome signs of harsh behavior and rhetoric among liberals and progressives, as well.

Last week, Hillary Clinton released “What Happened”, her account of why she lost the 2016 election. Because she unfairly included her tough primary contest with Sanders a factor that caused her to lose, Twitter exploded with ugly charges being hurled back and forth between supporters of both candidates. It may be useful to have a discussion of why Clinton lost, but insults and unfounded accusations make the exercise counterproductive and damaging.

If anything, the 2016 primary battle involved a principled debate over key aspects of domestic and foreign policy. Sanders challenged Clinton on issues like: the roots of income inequality and economic injustice; and the need to break the stranglehold that financial elites and corporate lobbyists have on health care, trade policy, the criminal justice system, and our political process, itself. He demanded that we think big and proposed goals like: increasing the minimum wage, ending trade deals that disadvantaged American workers, providing universal health care by expanding Medicare, and creating jobs by investing in infrastructure and renewable energy. Sanders also questioned foreign policies Clinton championed like the war in Iraq and the unbalanced US support given to Israel’s continued oppression of Palestinians.

In response, Clinton scoffed at Sanders big ideas, dismissing them as unrealistic. She argued, instead, for an incremental approach to addressing these same issues. The debates were heated and became personal, at times, but never did they sink to the level that was in evidence in last week’s Twitter wars.

The accusations made by Clinton, and amplified by her backers, that Sanders had hurt her chances to win are simply not true. He not only endorsed her, he vigorously challenged his supporters to follow suit, and then proceeded to do more than three dozen campaign events on her behalf. As he observed, his contest with Clinton was over. Now the choice was between Donald Trump and her, and he was committed to do all he could to help Clinton win.

There is a lesson here for Democrats as we approach the 2018 Congressional elections. Big ideas must be advanced and debated, but Democrats must not fracture as they debate. Polarizing hostile discourse will only breed more division while, at the same time, making real debate over issues less likely.

This past week, we saw yet another display of a lack of civility and the damage it can do to advancing an important policy debate. When protesters disrupted a press conference House Minority Leader, Nancy Pelosi, had convened to highlight the plight of young undocumented immigrants—the “Dreamers”—the tactics used by the demonstrators did more harm than good.

A few weeks ago, President Trump cancelled an Obama-era program that had allowed Dreamers to secure work permits and remain in the US. Trump gave Congress six months to pass legislation to protect the 700,000 young people who had registered in the program.

Pelosi, a long-time champion of the Dreamers is supporting such an effort. Because Democrats are in the minority in Congress, they will need Republican support to pass any legislation. Pelosi, therefore, invited a group of Dreamers to tell their stories at the press event, believing that if they were known and heard, she could win support for the bill.

Her event was shattered by another group of protesting Dreamers who shouted down Pelosi and those who were to have spoken accusing them of being “sellouts” and demanding that instead of saving just the Dreamers, protection must also be secured for all 11 million undocumented immigrants in the US. While their concerns might be understandable, their tactics were not. And instead of civil discourse, their actions created chaos and recrimination.

Of course, we must advocate for comprehensive immigration reform and an end to mass deportations. That remains our goal. But because the clock is ticking and, given Trump’s deadline, only a little over 5 months remain before the 700,000 Dreamers lose their protection. In other words, we can and must continue to elevate the perfect, while fighting now to save the good. And we must do so without attacking allies and behaving in an uncivil manner.

This is why I am so pleased to be a part of the important work of TSI. We hope to continue on the track of informing the public about critical issues, challenging Republicans and Democrats alike to think big about solutions to our most pressing problems, and doing this while engaging in civil discourse. That, we believe, is the way forward.