It’s been a challenging few weeks for the Bernie Sanders campaign, but that was probably to be expected. After some promising new poll results and some almost glowing media coverage (even from Bret Stephens!) there came a new round of attacks. Elizabeth Warren claimed that Bernie Sanders told her a woman couldn’t win the election, Joe Biden accused Sanders of lying about Biden’s long record of advocating cuts to Social Security, the New York Times disparaged Bernie’s “divisiveness” in its bizarre bi-endorsement of Warren and Amy Klobuchar, and Hillary Clinton said that “nobody likes” Bernie and said he “got nothing done” in Washington.

The criticisms themselves should persuade nobody. Clinton’s characterization of Bernie as an unpopular do-nothing is laughably wrong: He might be disliked in Washington (good!), but he is one of the most respected politicians in the country and packs stadiums. And his record of substantive accomplishments is impressive for an independent socialist operating completely outside the party infrastructure. Joe Biden has long advocated cuts to Social Security, and nobody should trust him not to make a “grand bargain” with Republicans slashing benefits. The Times’ comparison of Sanders to Trump is absurd: true, both are “divisive,” but Trump is “divisive” because he’s a nationalistic plutocrat and Sanders is “divisive” because he condemns nationalism and plutocracy with thunderous indignation. As for Warren’s accusation, it’s highly implausible that Bernie said anything like what Warren accused him of, but even those inclined to believe it should recognize that Warren’s accusation was a desperate and vicious attempt to destroy a rival campaign weeks before the Iowa caucus, not a good-faith critique.

Unfortunately, smears do not have to be fair to be effective, and as Bernie Sanders and his surrogates have had to spend time swatting away silly attacks, they necessarily have been less able to focus on making a positive case. After Warren’s attack, she appeared to tick upward in the Iowa polls and Bernie lost what had been a slight lead over Joe Biden. We should be very alarmed by the way attention has been drawn toward questions of who said what about whom, and away from the issues on which Bernie Sanders is clearly the strongest candidate (healthcare, environment, immigration, the workplace, foreign policy). Getting Hillary Clinton and the New York Times to hate you is a good way to get normal people to like you, and Bernie should welcome their scorn. But he also has to make the case that he is different from other candidates in a very important way, and that he is uniquely well-suited for running against Trump. We need to focus on making that argument, and making it as clearly and loudly as possible, so that it can be heard over the noise.

Of course, it’s complicated, because it’s impossible to completely avoid engaging with criticisms. Some people in the Democratic Party, even people I respect, have called for Unity and Civility and expressed discomfort at open hostility between Sanders and other candidates. In fact, Bernie himself went so far as to apologize after campaign surrogate Zephyr Teachout published an op-ed calling Joe Biden “corrupt.” Some people wish the Sanders and Warren camps could simply “set aside their differences” and focus on attacking Donald Trump instead. Personally, I think calls for unity are a mistake: If Sanders is to make the case that he is the best Democrat to take on Trump, it’s necessary for him to point out why he’s the best, which requires being critical of the character and records of the other candidates. Zephyr Teachout was right about Joe Biden: His record serving the interests of banks is corrupt and disqualifying, as well as a liability in a race against Donald Trump. Biden is the frontrunner at the moment, and unless his voters are shown very clearly why he is bad, they will have no reason not to vote for him. There are good and sincere progressives supporting Elizabeth Warren because they do not see what a disastrous general election candidate she would be, do not fully grasp how bad her record of deceitful and evasive statements is, and do not see how much damage her candidacy and her attack on Bernie is doing to the chances of having a progressive president. So we have to be blunt and not shy away from criticizing the other candidates in the name of a “unity” that only hurts Bernie.

Bernie himself, contrary to what media figures say about him, is very reluctant to “go negative”—he has been very soft on Biden, declining to talk about the worst parts of Biden’s record, and responded to Hillary Clinton’s remark that “nobody likes” him with the classy comment that “on a good day, my wife likes me” rather than with something more acidic like “I do not take tips on likability from Hillary Clinton.” But Sanders’ supporters can’t show the same restraint. We need to point out that Joe Biden has a bad record, and that at a time when the planet urgently needs an unprecedented level of political change, we can’t have someone who declares openly that “nothing would fundamentally change” if he won.

The next couple of weeks are critical: If Bernie wins Iowa on Feb 3, it will put him in a very good position, because he’ll probably win New Hampshire on Feb 11, and the media will have to start treating him as the frontrunner, and stop attempting to bury him. But winning Iowa is going to be incredibly difficult. Elizabeth Warren, even though she is losing, has been gaining and is still siphoning away voters who would otherwise go to Sanders, and while Joe Biden is lagging in fundraising, he is still at the top of Iowa polls. If Sanders loses Iowa to Biden, it will make the task ahead much more challenging.

There are two weeks to win Iowa for Bernie. That means everything must be done to get him over the top. If you haven’t already, download the Bern app and get involved. Persuade every Iowan in your life, and everyone who knows an Iowan, that this election is critical. In 2016, Bernie came close to winning Iowa, and if he had, it might have changed the whole primary. In 2020, winning the primary without Iowa is not impossible, but Iowa would sure help.

Here is a crucial fact for every Sanders supporter to remember: Passive support is not enough. If Bernie wins, the reason he will win is that his supporters are different to those of the other candidates. They do not just mark his name on a ballot. They change people’s minds. It’s critical to remember that polls do not change because of mysterious magical forces in the universe, they change because people make them change. This is why it was so ludicrous when in 2016, many Democrats would sit refreshing polling website FiveThirtyEight for reassurance. Every moment spent looking at and parsing the polls is actually hurting the chances of the candidate, because it is squandered time that could be used taking actions that change those polls. Bernie Sanders can indeed point to many good polls that show him doing the best in a matchup against Donald Trump and pulling ahead of Joe Biden nationally. But if he wins, it will be because he doesn’t spend any time thinking about those polls.

The worst thing that could happen right now is for people to assume that because Bernie is doing reasonably well, he doesn’t need them or they can become complacent. In fact, this is exactly the moment where we should assume we’re not going to win without renewed effort. Complacency killed Hillary Clinton’s campaign and it will kill this one. Every Bernie supporter’s actions right now should be measured by the single criterion: Does this help us win or not? At the moment, we are still losing. If the Iowa caucus were held today, polls indicate Biden would win. Thus we need to act in order to change that outcome. Let us think strategically, and see this as a contest of power to be won, not merely an argument to be on the right side of. Let us not have useless online disagreements, let us welcome people to the movement and do everything we can to persuade them, while not hesitating to point out why every other candidate is inadequate. I regret not doing more in 2016 to put Bernie over the top in Iowa, considering how close he ultimately came. I do not want to have that same regret again.

It is not clear that the Bernie Sanders campaign can prevail. Sanders is up against absolutely formidable opposition; he is taking on the powerful, and the reason they are “the powerful” is that they have power. The power to destroy those who disagree with them. But what is clear is that this is an unprecedented moment of political possibility: if it works, it will be transformative, and so it is worth doing everything right now to make it happen. We can soon pay attention to other things, but right now, we are just a few days from the first Democratic primary, and the best thing that could happen in American politics right now is for Bernie to win it. We must all do everything we can.

