In back-to-back weeks, the two major US political parties held their presidential nominating conventions. Intended to be unifying celebrations, the events highlighted the worst aspects of each party. Republicans shed all pretenses and emerged from their 20-year hate cocoon as full-blown, fear-driven neo-fascists, embracing despotic strongman Donald Trump. Democrats revealed the full extent of their corruption, shrugging their shoulders over leaked emails showing that the party operated essentially as an arm of Hillary Clinton’s campaign to undermine progressive populist Bernie Sanders.

Rather than making earnest attempts at unity, establishment Democrats spent their week seemingly doing everything they could to push Sanders supporters away. Perhaps the chief offense came when Debbie Wasserman Schultz, who has long held the ire and distrust of Sanders supporters, was rewarded with a position in Clinton’s campaign just after stepping down as DNC chair over the email controversy. In the face of such disrespect, not even Sanders’s own calls for unity could prevent many of his supporters from walking out of the DNC.

Yet some level of Democratic unity is essential if a Trump presidency is to be avoided. Trump has been steadily gaining on Clinton in the polls, holding just over her in the current RealClearPolitics average. Both candidates’ historically low approval ratings are now tied nationally. Alarmingly, many establishment Democrats seem less than concerned. Their willful ignorance is reminiscent of Karl Rove in 2012 when he refused to accept, live on FOX News, that Obama had won Ohio.

They are taking Sanders supporters for granted. Because Trump is so loathsome, they are apparently confident that Sanders supporters will turn out on Election Day to oppose him. Many will. But if Clinton’s greatest strength is that she’s not Trump, and she doesn’t offer Sanders supporters much to get excited over in the way of policy, she and the entire world may be in for a rude awakening in November.

Given the surprisingly few references to Trump at the DNC, the party seems to be hoping he will bury his own campaign under scandal without having to take him head-on.  This is also evident in their choice of attack ads, which largely feature clips of the divisive things Trump has said in the hopes they will be offensive enough to turn off Americans without the need for Clinton herself to say much of anything.

But Trump is no ordinary politician. He is the leader of a fascistic political cult who said it best himself when he said, “I could stand in the middle of 5^th Avenue and shoot somebody and I wouldn’t lose any voters, OK? It’s like, incredible.” No amount of casual racism, no amount of dangerous warmongering, not even the alleged rape of a 13-year-old girl or the prevalence of Russian oligarchs in his business interests can turn his supporters away.

The Clintons can fight dirty, and against Trump they should. They did it to Barack Obama in 2008 when they highlighted his foreignness by releasing a photo of a young Obama dressed in Muslim garb. They did it to Sanders, narrowly skirting campaign finance laws to collaborate with Super PACs and painting his progressive platform – which had broad national support – as politically unrealistic.

Two tactics need to be employed against Trump. One is, sadly, to stoop down to his level. Someone like Al Franken should be weaponized to insinuate Trump has a small penis and to call him ugly. Trump cannot take the high road; he doesn’t even know it’s there. He will self-destruct and embarrass himself. The other, more productive route is to win over Sanders voters by outlining a clear, powerful, progressive agenda for America.

Clinton shouldn’t stop with the vague, feel-good political talk of love trumping hate, but she needs to be more specific than she has been. Americans are concerned about jobs; Clinton should emphasize her plan to invest heavily in infrastructure programs. Americans loved that Trump was self-funding his campaign and now that he’s reneged on that, Clinton turning down big money could make her seem less corrupt and bring over lots of Sanders supporters who know a thing or two about grassroots fundraising.

Banking solely on the danger posed by Donald Trump to drive voter turnout is no way for Democrats to win the White House. This is especially true if the party continues to assume it can get away with whatever it wants in terms of snubbing or insulting Sanders supporters.

If Hillary Clinton becomes the next president, it will be because Sanders supporters are genuinely concerned about the environment and the nation’s minority groups, which will both be under relentless assault during a Trump administration. But it’s only the all-too-existential threat of Trump that gives Clinton any kind of chance of winning Sanders supporters over. The way she and the DNC have treated them, it will be hard to bring them around – and that’s assuming the DNC is smart enough to even try.