Bernie Sanders
Democratic presidential candidate Bernie Sanders in Arizona during a campaign rally on March 15, 2016.Getty Images

As an emotion, hope is a close relation of despair. Dissatisfaction with the present is the common factor — the difference lies in whether you believe that things might actually get better. If you've pinned all of your hopes for the future on one single critical event, it's very easy to slide into desperation if everything doesn't go as hoped. When you're in this mindset, high-risk behaviours can become increasingly appealing. There's a desire to regain some sort of control over the situation, even if your actions could be counterproductive.

All of which is a very roundabout way of saying that I understand, to some extent, where Susan Sarandon is coming from when she says she may not back Hillary Clinton, as the 'lesser evil' against Donald Trump. Though she didn't explicitly back the position herself, her statement that "some people feel that Donald Trump will bring the revolution immediately if he gets in, things will really explode" articulated the opinion of a fraction of left-wing voters, some of them Bernie Sanders supporters. Her broader claim, that she's unconvinced Clinton has much to offer, is a perspective shared by a larger number of people.

It's easy to attack Sarandon as privileged and thus insulated from the real risks of a Trump presidency. Certainly, there are very good reasons that black, hispanic and Muslim voters might find the difference between the two candidates more striking and important than a white woman. What's more, Sarandon's wealth and status as a Hollywood actress protects her in all kinds of ways. If things go really bad in the US, she could quite easily emigrate to Canada, Europe or pretty much anywhere else that took her fancy.

The thing is, however, it's not only people who enjoy the same luxuries as Sarandon who feel the same way she does. Though it has frequently been insinuated, there's no evidence that left-wingers who say they won't vote for Clinton are disproportionately privileged or unlikely to be affected by Trump's policies. Many people have taken this stance for reasons unrelated to the accelerationist perspective outlined by Sarandon .

Anecdotally, I know of several Muslim women who feel that Clinton's aggressive foreign policy means they can't, in good conscience, lend their support. For them, there is a hard line and 'lesser evil' arguments simply don't apply.

With people whose focus is mainly within US borders, something different is going on. The issue isn't that Hillary Clinton is going to make things worse, it's that they don't believe she'll make them any better.

Statistically, disengagement with politics isn't correlated with privilege but with poverty. In the 2012 presidential election, 80.2% of people earning more than $150,000 voted, compared with just 46.9% of those earning less than $10,000. When non-voters are asked why they don't bother, the answer is often the same: politicians are all the same and it doesn't make a difference who is elected.

In many cases, this isn't an opinion that people have given much conscious thought. It just seems an obvious truth that getting involved in politics isn't going to change things in any meaningful way. There are more important, immediate things to worry about. For Sanders supporters, who've obviously chosen to engage with electoral politics in some way, the psychology is slightly different.

Clinton tells voters that this is basically as good as it gets so they should stop filling their heads with silly ideas.

Though his policy positions aren't particularly radical by European standards, Sanders' candidacy inspired hope in people who'd otherwise given up on seeing their opinions and interests represented in mainstream politics. He represents a genuine break with the status quo. In contrast, Hillary Clinton is the status quo. More than any of the Republican frontrunners, even, she is the candidate of the establishment. Sanders' message is that real change is possible. Clinton tells voters that this is basically as good as it gets so they should stop filling their heads with silly ideas.

Of course, the counterargument is that change really isn't possible — at least, not the sort that Sanders' supporters are hoping for. Critics contend that the Vermont senator makes promises he won't possibly be able to deliver within the confines of the US political system. If he tries anything too dramatic, Congress simply won't be prepared to work with him. Sarandon blasted Clinton because "she doesn't even want to fight for a $15 minimum wage" but Hillary's supporters contend that she's just being realistic.

People want something to vote for, not simply something to vote against

Maybe they're right. It's quite possible that Sanders would find it extremely difficult to enact any of his most attractive policies. Given how much Obama has struggled with healthcare reform over the past several years, attempting to implement a single-payer system would clearly be an enormous challenge. Perhaps raising the minimum wage really is an impossibility. It is possible that there really is little that can be done to improve the lives of low-earning sections of the population.

If that's the case, though, can we really blame left-wingers for feeling alienated from the Democratic Party? If you tell people that almost everything they want to achieve is impossible, is it surprising that some of them might give up and opt out of electoral politics entirely? Both Trump and Cruz are such demagogues that stopping the Republicans is a fairly effective motivator, and many of Clinton's fiercest critics will reluctantly support her when the time comes, but hope requires a certain amount of positivity. People want something to vote for, not simply something to vote against.

US election 2016: Donald Trump addresses Nazi salute questionsIBTimes UK

For people who've dared to believe in the possibility of Sanders' political revolution, despair is a natural response now that dream is all but shattered. Briefly, it seemed that their views and interests might actually be represented in electoral politics for the first time in decades. Now, it's almost certain that this won't be the case.

Going from such a high to such a low is tough. It's hard to come to terms with the fact that the movement you're part of — the movement you invested significant time, energy and, often, money into building — could all be for nothing, at least in an immediate sense. The fact that people who backed a moderate, social democratic candidate talk of accepting the election of a proto-fascist to accelerate the revolution shows how powerful the desire to stay hopeful can be.

Can we really blame left-wingers for feeling alienated from the Democratic Party?

Obviously, it's an absurd argument. Even if a Trump presidency did provide the kind of social unrest they're hoping for, it's not obvious why they think things would play out in favour of the left. The thing is, the people saying these things do understand that, really, if they thought that it was anything more than a long-shot they'd never have supported Sanders in the first place.

Yes, many of them will be angry young white men who wouldn't suffer hardest if Trump was president. Obviously, people who are the direct targets of his hate will probably be less prone to such flights of fancy. Yes, also, someone as wealthy as Sarandon is a particularly poor poster woman for such a perspective. This is about more than just privilege, though. It's about the close relationship between hope and despair. In economic terms, many of the people who are angriest do have a lot of skin in the game.

Now that Sanders' supporters have experienced genuine optimism, many will feel like addicts desperate to get their next fix. It's going to be harder to persuade them to fall into line and back establishment Democratic candidates.

Across the Atlantic, the UK left has mounted a similar rebellion against the centrist Labour politicians who've generally relied on their support, and in this case the effort to select a party leader was overwhelmingly successful. There's no easy answer to the schisms that have occurred, but one thing seems certain: the left is increasingly unwilling to be taken for granted.