Donald Trump's Lunacy Reveals Core Truth About the Republicans

Since the election of Barack Obama, the Republican Party has proved that one of its central intellectual arguments was right all along. It has long claimed that evolution is a myth believed in only by whiny liberals – and it turns out it was on to something. Every six months, the party venerates a new hero, and each time it is somebody further back on the evolutionary scale.

Sarah Palin told cheering rallies that her message to the world was: "We'll put a boot in your ass, it's the American way!" – but that wasn't enough. So the party found Michele Bachmann, who said darkly it was an "interesting coincidence" that swine flu only breaks out under Democratic presidents, claims the message of The Lion King is "I'm better at what I do because I'm gay", and argues "there isn't even one study that can be produced that shows carbon dioxide is a harmful gas."

That wasn't enough. I half-expected the next contender to be a lung-fish draped in the Stars and Stripes. But it wasn't anything so sophisticated. Enter stage (far) right Donald Trump, the bewigged billionaire who has filled America with phallic symbols and plastered his name across more surfaces than the average Central Asian dictator. CNN's polling suggests he is the most popular candidate among Republican voters. It's not hard to see why. Trump is every trend in Republican politics over the past 35 years taken to its logical conclusion. He is the Republican id, finally entirely unleashed from all restraint and all reality.

The first trend is towards naked imperialism. On Libya, he says: "I would go in and take the oil... I would take the oil and stop this baby stuff." On Iraq, he says: "We stay there, and we take the oil... In the old days, when you have a war and you win, that nation's yours." It is a view that the world is essentially America's property, inconveniently inhabited by foreigners squatting over oil-fields. Trump says America needs to "stop what's going on in the world. The world is just destroying our country. These other countries are sapping our strength." The US must have full spectrum dominance. In this respect, he is simply an honest George W Bush.

The second trend is towards dog-whistle prejudice – pitched just high enough for frightened white Republicans to hear it. Trump made it a central issue to suggest that Obama wasn't born in America (and therefore was occupying the White House illegally), even though this conspiracy theory had long since been proven to be as credible as the people who claim Paul McCartney was killed in 1969 and replaced with an imposter. Trump said nobody "ever comes forward" to say they knew Obama as a child in Hawaii. When lots of people pointed out they knew Obama as a child, Trump ridiculed the idea that they could remember that far back. Then he said he'd "heard" the birth certificate said Obama was Muslim. When it was released saying no such thing, Trump said: "I'm very proud of myself."

The Republican primary voters heard the message right: the black guy is foreign. He's not one of us. Trump answered these charges by saying: "I've always had a great relationship with the blacks."

The third trend is towards raw worship of wealth as an end in itself – and exempting them from all social responsibility. Trump is wealthy because his father left him a large business, and since then companies with his name on them have crashed into bankruptcy four times. In 1990, the Pulitzer Prize-winning journalist David Cay Johnston studied the Trump accounts and claimed that while Trump claimed to be worth $1.4bn, he actually owed $600m more than he owned and you and I were worth more than him. His current wealth is not known, but he claims he is worth more than $2.7bn.