On both sides of the Atlantic, a hectoring old white man looms over the political left.

In the US, senator Bernie Sanders has finally announced his candidacy for a Democratic primary race filled with younger, more capable, versions of himself. In the UK, Labour leader Jeremy Corbyn is presiding over the left’s biggest split in decades. Neither looks likely to give up soon, and that’s a problem.

While the similarities between the two candidates have been long remarked upon, and the two old socialists themselves have even acknowledged using each others’ campaigning ideas, their policy priorities aren’t actually perfectly aligned—Sanders’ most radical policies would find a comfortable home with Britain’s centrist Liberal Democrats, while his history on guns and abortion would be on the hard-right for a British politician. However, the two men are almost identical candidates in all the worst ways.

Impressive policy shifts

Firstly, it bears noting that progressives in both countries have a fair amount to thank both men for—both have shifted their previously centrist parties towards leftist platforms that are genuinely popular with voters tired of the Blair-Clinton “third way.” These include policies such as Sanders’ Medicare for all, free college tuition, and $15 minimum wage, and Corbyn’s push for a “green jobs revolution,” railway nationalization, and an end to abusive hiring practices. They have driven a considerable amount of activism and enthusiasm, with Sanders racking up extraordinary levels of small-dollar donations and Labour membership surging under Corbyn.

Their platforms have had real impacts on national politics. The Democrats won back the House last year on “Better Deal” policies partly cribbed from Sanders’ 2016 campaign. While facing Corbyn, the leadership of the Conservative party has been taken out of the hands of a cabal of upper-class free-marketeers presiding over radical austerity, and handed to a flock of middle-class incompetents who—were they not tying themselves in knots over Brexit—would love to be trying to win over blue collar voters.

Both men should look proudly at these accomplishments, but they should let others take the helm. For all the impressive shifts Sanders and Corbyn have delivered in their respective political landscapes, their personal drawbacks pose more far more harm than good to the left in their countries.

Party schisms

Let’s start with the obvious: the rifts they have caused in their countries’ leftist parties. (Note that Sanders has still never joined the Democratic party.)

The 2016 Democratic primaries were fought with such bitterness, that, as the leader of a grassroots activist group told me almost a year after the election, “We literally cannot say the names Bernie Sanders and Hillary Clinton in any of our groups because people are still so split about it.”

For Corbyn, the divide is starker. This week saw the Labour party’s biggest rupture in living memory, with eight MPs quitting to form a new independent voting block in Parliament. The group hasn’t ruled out running against Labour MPs in marginal seats where they risk splitting the progressive vote.

Equally damaging is how the two have reacted to the rifts, showing uncannily similar levels of stubbornness. Many Clinton supporters blame Sanders in part for her loss to Donald Trump, suggesting his refusal to throw his weight behind her—and his holding out on conceding the race after it was clear she would win—led many Sanders voters to either stay home or even back Trump. Corbyn, meanwhile, simply refuses to engage with his critics. Labour’s deputy leader Tom Watson has begged for him to treat the MPs’ departures seriously, but Corbyn has merely said he is “disappointed,” without acknowledging the legitimacy of their grievances.

Overlooked women and minorities

The two politicians have so far failed to win power in large part because of their unwillingness to deal with issues of race and gender.

Sanders, who surrounded himself with largely white male advisers, has systematically declined to seriously consider racism and sexism as problems in their own right, instead viewing them as outcomes of widespread economic inequality. Unsurprisingly, Clinton trounced him among minority and female voters.

Since then, female staffers on his 2016 campaign have said there was both pay inequality and “an entire wave of rotten sexual harassment that seemingly was never dealt with,” such as one top staffer allegedly forcibly kissing a subordinate and another treating women “like his personal assistants.” Black staffers have complained of micro-aggressions, lackluster outreach efforts to African American voters, and feeling as if the campaign had black staff “just to say you have black staff.”

Sanders made an equivocal apology to those alleging sexual harassment, saying, “I was a little bit busy running around the country trying to make the case.” He has since made a more full-throated apology.

He has also exacerbated matters by stumping for an anti-abortion mayoral candidate and suggesting that it wasn’t necessarily racist for white people to feel uncomfortable about voting for a black candidate.

Corbyn tarnished his self-declared feminism in his first week as Labour leader, announcing a shadow cabinet with no women in the top three posts. Instead of acknowledging that he hadn’t properly considered the matter beforehand, as seemingly revealed by an interaction between Corbyn and a lieutenant overheard by journalists, Corbyn accused critics of “living in the 18th century.” His claim: that those jobs are now no more important than less prominent shadow cabinet posts like health and business secretary. A year later, when Labour named a roster of white men as its candidates for big city mayorships, a backbench Labour MP wrote: “I suppose feminism is out of the window when your brothers in arms want the jobs.”

The Labour leader has said that MPs who harass women “must be held to account,” but shortly after a Labour activist told leadership that an MP had sent her suggestive texts and made inappropriate sexual contact, the MP was briefly promoted. When another MP was revealed to have a history of making misogynistic and homophobic comments, it took days for Corbyn to suspend him.

Despite a lifetime as an avowed anti-racist, Corbyn has presided over a Labour party in which antisemitism has brewed to such dangerous levels that, when quitting the party this week, Luciana Berger, one of the most prominent Jewish Labour MPs, called the party “sickeningly institutionally racist.” Several men have been prosecuted for sending Berger antisemitic death threats over the years, but when the party found out about an assault threat last year, it told neither her nor the police. The fact that one Labour MP responded to Berger’s and others’ defection by suggesting they were funded by Israel says everything you need to know about the state of the party under Corbyn.

With the advent of Trumpism, Brexit, and #MeToo, the Anglo-American world is at a historic juncture on misogyny and xenophobia, in which the next leader of each country could either entrench existing ills or take a road of reconciliation and progress. Sanders’ and Corbyn’s permissive records on the subjects show they are in no position to do the latter.

Vapid foreign policies

While Sanders barely had a foreign policy in 2016, both men share an anti-imperialist worldview that can lead to troubling stances. Both have questioned their countries’ membership of NATO. Corbyn once suggested the military alliance set up to defend the West during the Cold War should “close down” and Sanders paradoxically called for it to be expanded to include Russia.

In the latest example of their distaste for interventionism, both likened international recognition of Venezuelan opposition leader Juan Guaidó as president to Cold War-era American imperialism, branding it “outside interference” (Corbyn) and “supporting coups” (Sanders). That’s despite Guaidó being backed by almost all of Latin America.

Often the rejection of intervention serves as a way of avoiding taking tough decisions, allowing them to continue a career-long pattern of criticizing from the outside without offering solutions. For example, both have opposed military action in Syria. That’s an understandable position, but it’s unclear how they would actually fix the problem. In one beat, Sanders called for a US military drawdown, then added, “Assad has got to go. ISIS has got to be defeated.” How exactly will that happen? Meanwhile, Corbyn insists that “diplomacy and not bombing” is the answer. However, diplomacy has failed time and again—as to what Corbyn would do differently, we are none the wiser.

Similarly, both are queasy about free market trade agreements, but they’ve failed to articulate what they want instead aside from vague protectionism. A Brexiter at heart, Corbyn’s refusal to really throw his campaigning skills behind the Remain cause is seen as one reason they lost. It ultimately took him until Feb. 2019 to detail what he actually wanted from a Brexit deal, and some of that may not even be tenable.

As Trump himself has acknowledged, he and Sanders have rather similar views on trade. Sanders told the Daily Beast last year, “[Trump] is identifying the problem correctly but I’m not sure that his particular solution at this moment is exactly the right one.” What solution did Sanders suggest? Platitudes about “a more comprehensive approach than Trump is laying out” and calling for Congress to “begin to rethink our trade policies.”

Unfit to govern

Both superb campaigners, Sanders and Corbyn have corralled such blind, messianic support that their followers are unable to acknowledge the obvious: neither man is capable of governing.

Corbyn has run the Labour Party as a shambolic autocracy. His aides once accidentally published his “enemies list” of 14 MPs, one of whom was included for the petty reason of telling a Corbyn ally to “fuck off.” He has systematically alienated swaths of his MPs. The group who left this week did so in part out of the belief that he would just be a bad prime minister.

The past six weeks should have been a time of reckoning for Corbyn. With Theresa May facing historic defeats in the commons over her Brexit deal, Corbyn had the chance to show real leadership and steer the talks in the direction that Labour’s europhile base wants. Instead, he hasn’t even forced May to rule out a ‘no deal’ Brexit, preferring to hope the Conservatives fall apart and he can take the helm of whatever mess they eventually leave behind. He put personal ambition ahead of the country’s needs at a time of national crisis.

The left is now definitively fractured in Britain. Any progressive government would likely need to work in coalition with the new Independent Group and perhaps the Liberal Democrats. The fact that Corbyn hasn’t even been able to hold the party together suggests he wouldn’t have the skills to run a coalition as prime minister. Labour membership is so supportive of his domestic policy positions that it’s hard to imagine a new leader taking the party in a radically different ideological direction—however, they could make it fit to govern.

As for Sanders, his failure to grapple with the intricacies of governing was put in excruciating view when the editorial board of New York’s leftist tabloid, the Daily News, skewered him with basic questions about how he’d implement key policy proposals such as breaking up the banks and jailing Wall Street CEOs.

If you think that was a one-off, look at his past. When Politico quizzed lawmakers on his record from decades in Congress, it found that his big picture thinking has “rarely…translated into actual legislation or left a significant imprint on it.” One political scientist found Sanders was a generally below average senator in terms of impact on legislation, as measured by successful bills authored and amendments passed. His only executive experience is as mayor of tiny Burlington. He lost three attempts at running for governor of Vermont—his best result was winning 14% of the vote as an independent in 1986. If Vermonters don’t think he’s up to running one of America’s smallest states, what are his chances of success in governing the whole country?

Sanders’ opponents in the primary are running on strikingly similar policies to his. The candidates also just happen to be more competent than him, either with more governing experience (whether via cabinet posts, law enforcement roles, or big city mayorships), better legislative chops, or more policy smarts.

The two old lefties have changed national politics in ways they couldn’t have dreamed of five years ago. Now they should return to their shared forte of heckling from the sidelines, and leave the matter of governing to others.