When Jill Stein turned up at the Democratic party convention last month, she was greeted by a small crowd of Bernie Sanders delegates chanting "Jill or Bernie".

The warmth of the reception afforded to the woman the Green party last week nominated as its presidential candidate indicates that while Mr Sanders may now have reconciled himself to Hillary Clinton's candidacy, some among the ranks of his supporters are transferring their affections elsewhere.

For refusenik Sandernistas, Mrs Stein - a Jewish physician from Massachusetts, who was her party's presidential standard-bearer in 2012 - appears a natural fit. Pledging to slash defence spending by half, introduce a Green New Deal and cancel student debt, she has made great play for the support of disaffected liberals, even floating the idea that she could stand aside and allow Mr Sanders to run as the Greens' candidate in November. Her stance has attracted the endorsement of the academic Cornell West, one of Mr Sanders' appointees to the Democratic party's Platform Committee.

Looks, however, can be deceiving. Despite, for instance, Mr Sanders taking a decidedly less pro-Israel line than Mrs Clinton during the primaries, Mrs Stein has adopted a consistently far more hostile approach. An advocate of ending US military aid to the Jewish state, she accuses the US of encouraging "the worst tendencies of the Israeli government as it pursues policies of occupation, apartheid, assassination, illegal settlements [and] blockades". The approach would be part of a new "ethical foreign policy" - one that brackets Israel and Saudi Arabia as violators of "our basic values of dignity and human rights". Unsurprisingly, the Greens are prominent cheerleaders for the BDS movement.

But, as Yair Rosenberg has suggested, while condemning Donald Trump's "neofascism", it is the campaign of the Republican presidential candidate, rather than Mr Sanders, which Mrs Stein's rhetoric more closely resembles. Like Mr Trump, Stein appears to thrive on promoting conspiracy theories. She's peddled the notion that wi-fi damages "kids' brains", appeased those who oppose vaccinations against childhood illnesses and questioned the validity of government statistics. Like Mr Trump, too, Mrs Stein deploys slashing rhetoric against her opponents: she's attacked Mrs Clinton's mothering skills, echoed conservative calls for the Democrat nominee to be prosecuted over her use of a private email server and suggested that President Barack Obama is a war criminal. Finally, Mrs Stein appears to have the same indulgent attitude towards Russian President Vladimir Putin as the Republican candidate, using a visit to Moscow last December to attack US foreign policy without uttering a murmur of criticism of her host's repression at home and expansionism abroad.

As Mrs Clinton's lead widens in the polls, Mrs Stein's candidacy may simply prove an irritating sideshow for the Democrats. However, in an unpredictable election year, the party is taking no chances, repeatedly warning of the dangers that, like Ralph Nader in 2000, the Green candidate may tip a closely fought race to the Republicans. Polls underline the dangers: one-third of Mr Sanders' supporters continue to refuse to back Mrs Clinton. A recent CNN survey suggested 13 per cent were planning to vote for Mrs Stein. While she secured just 0.4 per cent of the popular vote in 2012, the Real Clear Politics average currently shows the Green candidate polling just under four per cent; in June she hit seven per cent in one poll. Mrs Stein's numbers in battleground states with big student populations - such as New Hampshire, Virginia, Iowa and North Carolina - will be closely watched by the Clinton campaign.

Mrs Stein, however, appears unconcerned that she might help Mr Trump slip into the White House. A "neoliberal" Clinton presidency, she pronounced last month, will simply "fan the flames of this right-wing extremism. We have known that for a long time, ever since Nazi Germany". As the political commentator Jonathan Chait argued in response, Mrs Stein's plan appears to amount to stopping Mr Trump by electing him president.