So how about a theme song for the Trump presidency? Suggestions anyone? A certain Lily Allen number might come to mind. You know, the one that goes “F**k You Very Much”. Too coarse? Here in California, they are thinking more John Denver – “Leaving on a Jet Plane”.

The “Calexit” movement might sound gimmicky with its play on Britain’s rupture from the European Union, but sometimes secession movements gain unexpected traction. I remember the night Quebec came within a seal’s whisker of leaving Canada. And there was Scotland.

Emotion can blur common sense. The Quebecois were angry their francophonie was being disrespected and their economic weight underappreciated. Californians are as grizzly as the bear on the state’s flag right now. Donald Trump lost the state to Clinton by 4 million votes. And they reckon they could fare quite well alone. Their’s is the sixth largest economy in the world.

The sense of grievance has deepened in the two weeks since he was sworn in. A quarter of all immigrants in the United States live in California. And just over one quarter of the state’s population was foreign-born. It is highly alert to environmental issues too. You get the picture. His plan to wall off Mexico alone is an abomination from an immigration and an ecological standpoint.

And so, it seems, there actually will be an effort to detach it from the rest of the union. Last week, the California Secretary of State formally gave a group that calls itself Yes California the green light to begin collecting signatures to put a proposal for independence on the ballot when mid-term elections to Congress come around in November next year. They will need 585,407 of them, which they believe to be eminently doable, even it is likely to be quite expensive.

They also think it could pass. A Reuters-Ipsos poll conducted just after the inauguration suggested that breaking away was something that one in three Californians support already and no one has even started campaigning for it yet. When a similar poll was taken in 2014 to coincide with Scotland’s referendum only 14 per cent voiced support.

“We always thought that if we just connected with the people who thought about this, but didn’t tell their friends and family because they would be seen as kooky and weird, that the quiet population would become vocal,” Marcus Evans, vice president of Yes California, reflected to the Sacramento Bee.

Its approval would repeal clauses in the California Constitution stating that the state is an “inseparable part of the United States” and that the US Constitution is the “supreme law of the land”. According to the rules, a full referendum on separation could be called in 2019.

Are you hearing Denver yet? Don’t. First off, it ain’t going to happen because the rest of the country would have a say in the matter. As the lyrics go: “So kiss me and smile for me / Tell me that you’ll wait for me / Hold me like you’ll never let me go.” And hold they would. California would only be allowed to drift into the Pacific Ocean with an amendment to the US Constitution. That would require approval by two-thirds of the US Congress and ratification by three-quarters of the other states. Err, no.

(Getty (Getty)

Secondly, what seems like a really cool idea – “Up Yours, Donald” – is a terrible one. Consider the consequences. It would consign the rest of the country to Trump and his Republican successors for ever and a day. Without their Californian brethren, the progressive Democrats would face political oblivion. Only so many people can fit on the island of Manhattan.

And if California envisages casting off peacefully, Trump might think differently, posing as a modern Abe Lincoln to humiliate the rebellious rump and force it back into the fold with cannons if necessary. Trump wins the second Civil War.

So, yes, we are surely in Mama and Papa-land at this point. As in “Calexit Dreamin’”. But there is another point to be made here. Abandoning ship because of Trump is the wrong answer.

This is a message not just for Yes California. It also applies to all my friends who have been saying, with ever growing urgency, that they want to exile themselves from the United States because they can’t abide what is happening. Many are simply embarrassed to be here with Trump behaving as he is. It has been a topic of conversation in my own household too.

I say, stay and fight. You won’t be alone. When half a million gathered in Washington for the Women’s March the day after the inauguration, 20,000 assembled at the Capitol Building here in Sacramento. This is not a big city. And there is a surge already of young progressives everywhere signing up to run for local, state and national office next year to roll back Trumpism.

It was the British singer songwriter Frank Turner who may have already delivered the anthem we should be looking for. He performed it for the first time in California, aptly – at San Francisco’s Warfield Theatre – last Sunday. It’s called “Sand in the Gears”.