Acute political insight hasn’t characterised much of the enthusiastically pro-EU movement over the last year or so. The decision to hype up, then try to play down, the renegotiation backfired badly. The calculation that overblown economic fears would seal the deal in the referendum went awry. They steamed to disaster, convinced they were set to win easily.

After the referendum, most of the sharpest players on the former Remain side recognised reality and chose to accept the result – one even became Prime Minister shortly afterwards.

Those left as the skeleton crew on the Remain ship were the most fervently committed, the most dismayed by the referendum result and the most contemptuous of the concept of Brexit. None of these characteristics is likely to improve the acuity of one’s judgement, and so their decision-making has declined accordingly. Week to week, they have stumbled (with one notable exception) from one wishful, vain hope to another – perhaps Leave politicians could be prosecuted for “lies”; perhaps a court case could prevent the Government triggering Article 50 using the Royal prerogative; perhaps MPs would vote against Article 50; perhaps peers would vote against Article 50; perhaps MPs would accept amendments limiting Article 50; perhaps peers would insist on the amendments twice rejected by MPs, despite the risk of a constitutional crisis…and so on, and so on.

Every supposed chance to ignore the referendum outcome has proved to be illusory. Each time, a few more of the holdouts recognise that their cause is doomed and accept reality, even if they dislike it. As the movement dwindles, its search becomes more desperate and its powers of judgement decline further. This will be a familiar process to veteran Eurosceptics – it is the same route by which parts of our cause got sidetracked and bogged down in barmy theories about medieval treason laws and the like. Imagined silver bullets which will banish the grim reality of electoral defeat are superficially attractive to the desperate, but poison to a political campaign.

With Article 50 set to be triggered, there’ll be another thinning of the Remain herd tomorrow – another tranche will become resigned to the process. But the remains of Remain will continue their search for a way out. Some are off in Dublin, pursuing lawfare in the hope of revoking Article 50. Others cling to the hope that Leave voters will rise up against Brexit, if only they can convince them that it is pointless.

One problem with this latter approach is overcoming the work they themselves have done in recent months to harden Leaver resolve. Surprisingly, the Eurosceptics’ experience of being derided as old, ignorant racists hasn’t left them in a listening mood.

A bigger problem is that the hardcore Remainers who soldier on lack any understanding of what makes Leave voters tick or how Brexit works. Take, for example, some of the reaction to David Davis’s appearance on Question Time last night.

The Brexit Secretary said this about post-Brexit immigration policy:

“I cannot imagine that the policy will be anything other than that which is in the national interest. Which means that from time to time we will need more, from time to time we will need less. That is how it will no doubt work and that will be in everybody’s interests – the migrants and the citizens of the UK.”

To any reasonable observer, that’s a statement of the obvious. But for some the second sentence is crucially important – he’s said that immigration could rise and fall outside the EU! Just imagine how angry Leave voters will be about the idea that immigration might rise. This must prove to them that Brexit is futile. Surely now they will abandon their cause and decide to stay.

Well, not really. For a start, Davis’s words are deliberately unsurprising – circumstances, economics and demographics change from year to year and decade to decade, and policies alter accordingly. More importantly, the whole point of voting Leave was that immigration and other policies should be decided democratically by the UK. After we leave the EU, any rise or fall in immigration will happen on the say-so of our elected Parliament and nobody else.

If voters in 2020 opt for lower immigration, the Government of the day will have a duty to implement that. If, in 2025 voters, decide they want a specific rise to let in more social care nurses, or car mechanics, or doctors, then that will become the policy.

First and foremost, people wanted the right to control these issues. No doubt voters currently want less immigration – the Conservative Party’s troubled pledge to reduce net migration to “tens of thousands” was made specifically to win votes on the back of that opinion. I suspect some of that feeling is inflated by frustration that the current policy is set undemocratically, so might soften a little once we leave the EU. Furthermore, if advocates of higher migration successfully campaign to change people’s minds in years to come, then the parties will fight for those votes instead.

That’s how democratic politics works. Theresa May clearly gets this, which is why she has rejected any continuation of free movement. She knows that breaking that promise would be politically fatal, and so we will soon have taken back control of border policy as promised. A quote in which Davis explains how that works isn’t a slam dunk, it’s a demonstration that he understands what Brexit means.

Will some people be aghast at Davis’s words? Certainly – some because they want practically no immigration ever, and some because they are seeking to mobilise outrage to keep UKIP going. But while they may become less likely to vote Conservative, they are even less likely to abandon Brexit because of this. If you voted Leave out of opposition to immigration, then your response will be to press for a more restrictive post-Brexit policy, not to give up hope and embrace the proven uncontrolled immigration brought by EU membership.

Yet again, those hoping to keep us in the EU are getting excited over nothing. While they chase mirages, the post-Brexit political landscape is slowly being sculpted without their involvement. After we leave, the Government will present a new immigration policy – probably one based on work permits – and there’ll be a debate about its rules and numbers, both inside and outside Government. The fact we are already discussing what that policy should be is a sign that things are moving on, and Brexit is increasingly assumed to be an inevitable fact of life.

The longer people paint their faces with yellow stars and fantasise about Remaining, the longer they absent themselves from shaping the country after Brexit. They may well end up very disappointed if by 2019 policies have been formed that they would have liked to oppose or alter. That abstention is optional, and it is a serious mistake – it could take them years to make up the ground they are currently surrendering.