I know there are many voters in this election who are attracted to Green Party policies - whether it's lifting the minimum wage to £10 per hour by 2020, bringing the railways back into public hands, or paying a citizens' pension that means no older person need live in poverty.
But they have doubts, because what we are saying is very different to what the Tories, Lib Dems and Labour are saying. Those parties are saying that austerity is inevitable, that the rich can't be taxed, and that benefits can't be paid to those who need them. And they are saying, by their silence, that climate change can't be tackled.
The question was put to me very clearly by some student journalists in Liverpool at the weekend: "aren't you too idealistic? Are your policies realistic?".
My answer to them was simple: we are the realists.
It is the other parties who are stuck in a failed 20th Century politics that's delivered an economic situation, a social arrangement, and a treatment of the environment that clearly cannot continue. The approach of successive governments under Thatcher, Blair, Brown and Cameron - watching as the gap between rich and poor has grown, selling off our public services, and paying at most lip service to environmental protection, has clearly failed. And that explains the sense of frustration, anger and disillusionment so evident among voters today.
And yet the business-as-usual parties are carrying on as though the UK's fraud-ridden, overinflated and out-of-control banking sector wasn't a massive threat to the economy; as though having more than 20% of workers on less than the living wage were sustainable; as though we could continue to treat the planet as a mine and a dumping ground without disastrous consequences.
And despite all the evidence, they maintain that austerity is the way out.
This week Nobel prize-winning economist Paul Krugman pointed out that continuing austerity, whether the "light" version offered by Labour or the "heavy" version of the Conservatives, does "major damage" - and that the UK seems "stuck on obsessions that have been mainly laughed out of the discourse elsewhere".
But we don't need to look to economists to see that our economy, as it is now, is not working.
The growth figures out this week show manufacturing and construction falling back, while the services sector, funded largely by soaring consumer debt, is holding up the overall figure - clear evidence that this government has failed in its aim to rebalance our economy away from the financial sector and bring manufacturing back to Britain.
We've got a housing policy that's working primarily for the gain of private landlords, particularly those owning large numbers of houses, who last year received £9.3billion in housing benefit, while also collecting more than £5billion in mortgage rate relief. That's while 1.8million households languish on waiting lists for social housing and, particularly in London, the concept of affordable housing has become a farce: you'll need a household income of £100,000 for an "affordable" four-bedroom flat in a major new development.
We've got small businesses facing the same tax rate as the multinationals, despite the fact that we know small businesses contribute far more to their communities and to society than the corporate giants. Under the last Labour and Tory governments, which reduced and then scrapped the difference in corporation tax paid by small and large businesses, small businesses have been paying a larger and larger share of corporation tax. Larger firms, meanwhile, often opt to avoid this tax altogether. They're relying on the rest of us to pay tax for the roads their delivery lorries need, the hospitals and schools their staff and customers need, and the benefits needed to supplement the low wages they pay their staff. These businesses - the real scroungers - siphon money out of the UK tax pot, and far too often into tax havens.
And then there's the state of our natural world. Whichever measure you look at, it is dire. Globally, we've lost 50% of the world's wild animals in the past 40 years. Locally, we've got air pollution levels that are killing up to 60,000 people a year and reducing the capacity of our children's lungs, a disability that will stay with them for the rest of their lives.
And climate change is a huge, pressing issue on which this government - which once dubbed itself the 'greenest ever' - has stalled action, while pursuing its fracking fantasy. Their failure to deliver on their environmental promise has denied small businesses and communities the chance to seize control of their energy supply from the "Big Six". It has left us trailing behind on renewables while much of the rest of the world powers ahead, and led to cold homes, costing the NHS £1.4billion a year and causing many thousands of excess winter deaths.
It is realistic to think we can have a different kind of economy and society. It is possible to create a fair and just arrangement in which no one need fear being unable to put food on the table or keep a roof over their head; in which businesses big and small pay their way to fund the infrastructure their profits depend on; in which we all collectively live within the environmental limits of our planet.
It is profoundly unrealistic to think we can continue as we are.