As the Labour leadership election draws on, Jeremy Corbyn is bringing to mind Lady Caroline Lamb’s description of Lord Byron: “mad, bad and dangerous to know”. Whether it’s claiming that after-work drinks are sexist or picking a fight with Richard Branson, Corbyn retains his capacity to inspire adulation in some and amusement in many more.

The longer the campaign goes on, however, the more it starts to feel – well, rather American. In particular, Corbyn’s strategy has echoes of a man he would probably deny having anything in common with at all: Donald Trump.

Such comparisons are, of course, nothing new: Corbyn and Trump have already been compared by many. While their policies are radically different, they are both unexpected candidates for political primacy determined to rail against the elites, who have failed to win the support of many within their own party.

However the connection runs much deeper. Corbyn and Trump are both motivating their supporters – to an unprecedented extent – by attacking the enemy within. For Trump this is the Mexicans, his “beautiful border wall” becoming a centrepiece of his campaign. For Corbyn this is the rich and the bankers.

Attacking a single group – especially the wealthy – is not an unusual tactic for British politicians. But doing it with such enthusiasm is less common. Yes, it ensures that Corbyn’s followers see him as a “principled” leader. But it also opens up further division within our society: Labour’s enemies (or rather Corbyn’s enemies) are not just wrong, but evil.

The European Union referendum in June, while occasionally ill-tempered, was marked by the way politicians were willing to cross party lines. On the Remain side, for example, David Cameron joined with Tim Farron, Gordon Brown and Sadiq Khan. There was one notable absentee: Jeremy Corbyn. John McDonnell, his shadow chancellor, claimed that for senior Labour figures even to share a platform with the Conservative Party would discredit Labour. Corbyn may be notorious for his dim view of Tory politicians, but refusing to work with them on a cross-party cause polarises politics.

Not only is Corbyn restricting views coming from other parties, but even ones from within Labour. The Democrats and the Republicans are reviled for their inability to work together in the interest of their own nation. In just the same way, Labour are closing themselves off from others, and even their own elected MPs.

That this has happened is in large part down to Labour’s voting rules. Until recently, its leaders were elected by politicians, not the people. Now, that has changed. Since Corbyn has already ostracised by his own MPs, suffering mass resignations from his front bench, he will have to maintain the support he gained from party members to stay in power. He has already started the American practice of hosting huge rallies which sell him as a brand. This dependence on support from those that are addicted to his style of politics is very similar to that of a presidential candidate. But as we have seen with Trump, they demand stronger and stronger meat to keep them happy.

For many who were alienated by the Blair years, Jeremy Corbyn seemed a refreshing political voice. However, his style of campaigning and conducting politics is leading us down a dark and dingy road.