For many leftwingers PJ O'Rourke occupies a unique position. The famed American humorist and once notoriously hard-living journalist is the Republican that you liked. His caustic wit and warm humanity shone through his writing even when he was attacking your most firmly held political beliefs. Also, he loved a drink and wrote for cool magazines like National Lampoon and Rolling Stone. He seemed like he would be a lot of fun to prop up a bar with.

So it is comforting that within moments of settling into a chair in a borrowed office in downtown Chicago that O'Rourke casts his eyes thirstily around the room. "Can I offer you guys anything? God knows there might be a minibar in here," he says in a growly voice of hope, but not expectation.

Alas the mid-afternoon timing prevents an alcohol order. But if O'Rourke is still on the lookout for good times, the same cannot be said for his writing, which has taken a decidedly dark and despairing turn. His latest book's title says it all. "Don't Vote," it shouts on the cover before adding a punchline: "It Just Encourages the Bastards."

Don't Vote is, to say the least, an angry book. It attacks the entire gamut of American political life – but especially the left – in no uncertain terms and in salty language.

"Politics is a vulgar fucking subject," O'Rourke writes by way of apology for his repeated swearing. "I have resorted to barnyard words because of the amount of bullshit, horseshit and chickenshit involved in politics," he adds. Yet if anger is the American political theme of the moment – and much polling data suggests it is – then O'Rourke has caught the mood of much of the nation perfectly.

O'Rourke's thesis is simple: politics and nearly all politicians suck. The solution is to have less of both of them and the only people lobbying for that are rightwing, libertarian-leaning conservatives like him. They want the government to do less, spend less, take less and essentially leave people and corporations alone. If they did so, O'Rourke believes, it would make people generally and Americans in particular happier, wealthier and free from the harmful attentions of such interfering do-gooding elitists as, for example, Barack Obama.

Obama brings out a look of despair on his face and the sort of language that one usually associates with Tea Party movement members at a Sarah Palin rally. Far from being the infuriatingly moderate Democrat that most leftwingers believe Obama to be, the president is a socialist, believes O'Rourke.

"In Europe what he is doing would be called socialism. But because this is America you can't call him that! But this is Labour party stuff: 1945 Labour party stuff ... he is a leftist and he is a collectivist. He buys into all that stuff."

That does not make O'Rourke happy. But he believes it does not make the rest of America happy either and, watching the Democrats prepare for a likely devastating defeat in next month's midterm elections, he could be right. O'Rourke thinks Obama could soon end up a footnote in history, reduced to a blip by over-reaching the power of a government that many Americans have always been sceptical of. "He has got every chance in the world of being a one term president. He could easily go down in history as the 'funny name president' replacing Millard Fillmore in the minds of future schoolchildren," he says. Fillmore occupied the White House from 1850 to 1853 and is not known for much more than having a name that sounds like a breed of duck.

O'Rourke's words carry a strong draught of Tea Party. "I certainly talk to a lot of people with Tea Party-ish tendencies," he says, seeing in the movement's demands for less spending the expression of the small government ideas that his book lobbies for. "Fiscal conservatism is just an easy way to express something that is a bit more difficult, which is that the size and scope of government, and really the size and scope of politics in our lives, has grown uncomfortable, unwieldy, intrusive and inefficient," he says before adding a trademark kicker: "Too damn big!"

Don't Vote is a break with O'Rourke's traditional style. From his bestselling Parliament of Whores, in which he mocked the US government, to Holidays in Hell, in which he detailed his travels in some of the world's most dangerous places, he has generally preferred to point out the foibles of others, rather than suggest how to mend their ways. "No humorist is under any obligation to provide answers and probably if you were to delve into the literary history of humour it's probably all about not providing answers because the humorist essentially says: this is the way things are," he explains before admitting he is now breaking this rule. "Not obligated is not the same as forbidden from."

Don't Vote is something of a manifesto. It has a long section titled: What is to be done? In it O'Rourke argues for a massive stripping-down of what government does that runs from getting rid of Obama's healthcare reforms to not bailing out banks in future. But he puts the onus for doing all of this on ordinary Americans. It is reform from the bottom up, not top down. By doing things for themselves on a small scale and as locally as possible, Americans can be more self-sufficient and stop looking at politicians and government to do things. He is tapping into a growing stream of rightwing thought in America, which has stronger and stronger libertarian leanings and is finally abandoning the last vestiges of Republican paternalism.

It has echoes in Britain too, where David Cameron's "big society" plans are anything but big government. Instead Cameron too aims to strip power from the state and give it back to the individual, in a collective admission that government is failing. It is a seemingly odd stance for any self-respecting, and apparently self-loathing, politician to take. But these are odd times. The Tea Party wave is cresting at a time of immense economic distress. There are millions of unemployed Americans caught in the middle of a foreclosure crisis. There are wars being fought abroad, banks being bailed out and then granting their top employees huge bonuses and – in the mind of O'Rourke – a huge extension of the state in the form of "socialised healthcare". That is why he has greeted the rise of the Tea Party with enthusiasm. "It is a positive development in that it is a broad-based populist movement that is asking less of its government, rather than more, which is almost unheard of. Almost all populist movements, good ones and bad ones alike, want something more," he says.

Certainly O'Rourke – like many in the Tea Party – can be just as witheringly critical of elements of the Republican party as he can the Democrats. He has long embraced a social liberalism and freewheeling hedonism that is at odds with many Republican leaders (at least in their public lives). After all O'Rourke is a former hippy and almost-Marxist who makes no bones about having enjoyed many of the fun physical and pharmaceutical benefits of the 1960s and 1970s. Asked when he was happiest, he grins sheepishly. "There are happy moments that we really are not going to talk about," he giggles. But he has committed a good deal of them to print: he wrote an uproariously funny essay entitled How to Drive Fast on Drugs While Getting Your Wing-Wang Squeezed and Not Spill Your Drink. Needless to say he has never been a hit with the family values wing of the Republican party.

Which is ironic as O'Rourke these days pretty much lives up to their homely vision of family life. At 62, he has long put his crazy days behind him. It has been many years since he was a Rolling Stone writer and his print home now is often the conservative Weekly Standard. His actual home is a rural farmhouse in New Hampshire where he lives with his second wife, three kids and dogs. He is clearly devoted to family life despite a punishing book tour and speaking schedule that is keeping him wearily on the road. When discussing happiness, he is drawn to family life like it is a magnet. "There is that kind of happiness. There is the love and marriage and family kind of happiness, which is exceedingly boring to describe but nonetheless is important to have and dreadful not to have," he says. Perhaps this is because of a recent brush with mortality. Though O'Rourke often faced extreme danger in his days as a foreign correspondent, he came closest to it with a diagnosis of anal cancer two years ago. In characteristic style he wrote about it with a mixture of pathos and humour. "I looked death in the face. All right, I didn't. I glimpsed him in the crowd ... I have, of all the inglorious things, a malignant haemorrhoid. What colour bracelet does one wear for that? And where does one wear it?" he complained. Luckily the cancer had a 95% survival rate and radiation and chemotherapy appear to have put him in the clear. "I feel fine," he says. He has regular checkups to make sure he remains in remission. "I've become someone's nice little earner," he says with a laugh.

This does not sound like the angry O'Rourke who wrote Don't Vote. It sounds like an older man who has found contentment. But he remains a satirical commentator on politics and is bound to reflect its trends. "It is fun to write about. It is the same reason I went to cover wars. Other people write about sports. I am not writing about it because of its inherent value," he says.

And he still writes well. Don't Vote is full of zingers and pithy one-liners that amuse, inspire and horrify at the same time. Take his intentionally short chapter on the issue of climate change. It is one page and begins with the words: "There's not a goddamn thing you can do about it." By way of explanation he adds: "There are 1.3 billion people in China and they all want a Buick." He accuses western leftists of being self-deluding hypocrites when they raise taxes on people wealthier than themselves as a way of creating a more just society. It depends on your perspective, he argues, pointing out that even a poor westerner is unimaginably rich to a developing world slum-dweller.

"You're farting through silk as far as that person in Karachi who's looking for a job as a suicide bomber is concerned ... let he who is without anything anybody wants cast the first vote," he writes. Even if you do not agree with him, it is no wonder O'Rourke is most quoted living writer in the Penguin Dictionary of Modern Humorous Quotations.

But beneath the gags there is a deeper and more sophisticated layer of political philosophy. O'Rourke does not exactly wear his learning on his sleeve, but it is definitely there on his bright, shiny corporate cufflinks for those who want see it. He frequently references names as varied as 18th-century philosopher Jean-Jacques Rousseau, free market guru Milton Friedman and author and radical Thomas Paine.

He regularly quotes the Cato Institute, the Washington thinktank whose libertarian views most closely match his own. None of that necessarily means O'Rourke is right. Or that any liberals reading his work will suddenly cast aside their love of the state and walk into a free market future together with their newfound conservative pals. But it does mean that O'Rourke is serious about his jokes. Or at least jokes about things he takes seriously.

But one senses it is now becoming just a job, even if an enjoyable one. At the end of the interview, professionally posing for a photograph while puffing on a small cigar, O'Rourke confesses that his real passions now lie elsewhere. "I like making things. I have a wood shop at home. I am a terrible carpenter but I love doing it. I am blissfully engaged doing that but I do not think anyone looking at the products of my labour would rush to hire me. I just built a dock out into our pond and so far it has not collapsed and hurt any of the children, but I would not exactly call it level," he says. Thus O'Rourke, who wanted to be an architect when younger, is fated to continue to use wordplay to make a living. "I write because I like to make things and the only things I am good at making things with are words," he says with, perhaps, just a hint of regret.

Don't Vote: It Just Encourages the Bastards is published by Grove Press, priced £16.99. To order a copy for £12.99 with free UK p&p, go to theguardian.com/bookshop or call 0330 333 6846

The world according to PJ O'Rourke

The French are a smallish, monkey-looking bunch and not dressed any better, on average, than the citizens of Baltimore. True, you can sit outside in Paris and drink little cups of coffee, but why this is more stylish than sitting inside and drinking large glasses of whiskey I don't know." Holidays in Hell (1989)

"The Democrats are the party that says government will make you smarter, taller, richer, and remove the crabgrass on your lawn. Republicans are the party that says government doesn't work, and then they get elected and prove it." Parliament of Whores (1991)

"Liberals have invented whole college majors – psychology, sociology, women's studies – to prove that nothing is anybody's fault. No one is fond of taking responsibility for his actions, but consider how much you'd have to hate free will to come up with a political platform that advocates killing unborn babies but not convicted murderers. A callous pragmatist might favour abortion and capital punishment. A devout Christian would sanction neither. But it takes years of therapy to arrive at the liberal view." Give War a Chance (1992)

"There is no virtue in compulsory government charity, and there is no virtue in advocating it. A politician who portrays himself as caring and sensitive because he wants to expand the government's charitable programs is merely saying that he is willing to do good with other people's money. Well, who isn't?" Why I am a Conservative (1996)

"The idea of a news broadcast once was to find someone with information and broadcast it. The idea now is to find someone with ignorance and spread it around." Peace Kills (2004)

"How would Adam Smith fix a mess such as the current recessionary aftermath of a financial collapse? Sorry, but it's fixed already. The answer to a decline in the value of speculative assets is to pay less for them. Job done. Don't Vote (2010)