If you had told me in the spring of 2016 that three years later I’d be touting the merits of the Bernie Sanders campaign—taking flak from Hillary Clinton supporters for not being loyal enough to her—I would have laughed and asked what alternate reality you lived in. But life and politics have a way of taking unexpected turns, and here I am writing about the considerable strengths Sanders brings to the 2020 election.

I do so not to endorse Sanders or to minimize the large and diverse Democratic field. It is early in the primary season, and voters should take the time to assess all their options. I am going through that process myself, studying how the candidates campaign, how they deal with the corporate media, what policies they’re putting forward. I’ve focused on Sanders in recent weeks because I am concerned that festering anger from the 2016 primaries is causing a rift in the electorate that Donald Trump and the Republican Party can—and will—exploit.

Sanders is unquestionably in the top tier of candidates for the Democratic nomination, and it would be an epic act of self-destruction for Democrats to plunge into an internecine conflict over his candidacy at a time when they need to marshal every asset to defeat Trump and his GOP cronies. I am calling on Democrats, progressives, and leftists to hit the pause button, to table our disagreements, no matter how intense, as we fight to preserve the rule of law and the last semblance of our democracy. We owe it to ourselves and our country.

My political and personal evolution since 2016 has caught some people off guard. I’m often asked how a staunch Clinton advocate and former Sanders critic could reverse course. The answer is simpler than it appears. I spent 15 years before the 2016 election as a progressive activist, a critic of the Democratic Party’s meekness in the face of GOP extremism, and a supporter of the policies Sanders promotes.

After months of reflection about my role in the 2016 primaries, I realized I was among the far too many Clinton and Sanders supporters who got caught up in an ugly family dispute that spiraled out of control. We’ve all experienced those explosive fights. In the heat of the moment, we see each other as enemies rather than human beings who largely have the same goals. So I began to reach out to repair what had been broken. On Twitter, I unblocked Sanders supporters who I had argued with. I tried to see things from their perspective, and I asked them to do the same. There’s still some residual anger and skepticism, but the healing process has given me invaluable perspective, and I can now look at the 2020 primaries through a clear lens.

This is what I see: An extremist GOP that is methodically consolidating power, stacking the courts with far-right ideologues and making a mockery of the rule of law. It is everything we feared from a Trump presidency, and worse. And I see that Sanders is a strong front-runner for the 2020 Democratic nomination. He leads Trump in several match-up polls. He has millions of dedicated supporters. He is raising tens of millions of dollars from small donors. He is a seasoned campaigner with a presidential race under his belt.

Virtually every state and national poll shows Sanders at or near the top of the Democratic field. Polls are fluid at this stage, but he is a known quantity, and his base of support is solid. His proven appeal to young voters and independents is a powerful asset, and his ability to deliver a well-crafted and unapologetic progressive message to Americans across the political spectrum is crucial if Democrats hope to take on an increasingly extremist GOP.

He is not without his flaws and inconsistencies. He needs to do more outreach to black voters, the base of the Democratic Party. His positions have sometimes been at odds with the principles he touts. But that holds true for every candidate and politician.

Most important, Sanders has played a central role in advocating enlightened, compassionate, forward-looking policies like Medicare for All, free public college, a living wage, and more. In the heat of the 2016 primaries, I was reluctant to give him credit for moving the national debate to the left. But it is impossible to deny the important role he played and continues to play in countering the far right’s extremist ideas.

During the most ferocious debates of the Clinton-Sanders contest, I repeatedly implored Sanders supporters who disliked Clinton to focus on the ultimate prize: defeating the authoritarian right. I argued that her positions were immeasurably superior to Trump’s and that tearing her down was a grave mistake when we faced the prospect of white-nationalist rule. The same holds true today for Sanders. Trying to hobble his campaign is a reckless mission.

The stakes couldn’t be higher. The recently released report by special counsel Robert Mueller reveals extensive corruption and lawlessness by Trump and his cronies. Republican leaders have abdicated their constitutionally mandated oversight in order to cover for Trump’s abuses of power. Trump has convinced his MAGA followers that journalists are “enemies of the people.” Meanwhile, the powerful right-wing media apparatus, spearheaded by Fox News, churns out a steady stream of spin and propaganda designed to stoke fear and division among Americans. White House officials are engaged in a relentless assault on truth and facts, undermining the sense of a shared reality essential to a functioning society. Their declarations have become increasingly Orwellian. “What you are seeing and what you are reading is not what is happening,” Trump insisted. Rudy Giuliani told Chuck Todd that “truth isn’t truth.”

Under cover of this Trumpian chaos, fundamental rights are being eroded by a Republican Party that lacks even a rudimentary moral compass. Migrant children are being stolen from their parents and detained in frigid holding cells. The EPA has become an arm of big polluters. The poor and sick are losing health coverage to fund tax cuts for the superrich, who can buy eight-figure condos on Manhattan’s Billionaires’ Row while nearly half the population can’t afford a $400 emergency expense.

Alarmingly, the ferocity of the GOP’s attack on our norms and values is met with timidity from the Democratic Party leadership. Even after grassroots activists and voters generated a 2018 blue wave that swept Democrats back into power in the House, the leadership has proved incapable (or unwilling) to rise to the historic challenge of facing down encroaching fascism. There are no saviors coming to rescue us. We must become our own leaders. To defeat Trump and to reverse the rising tide of white nationalism that threatens the foundations of our democracy, we must have the courage to set aside old grievances for the greater good. Sanders is not the only candidate who can defeat Trump, but he’s certainly one of them. And he should not be treated as the enemy.