WASHINGTON, DC – Donald Trump, the Republican Party’s presumptive nominee to contest the United States’ presidential election in November, is clearly not a standard Republican. The party’s leaders and elected officials fought against him during the primary, and many are still reluctant to endorse him. Trump is now aligning some of his policy proposals with mainstream Republican ideas, but he is also clearly determined to retain his distinctive identity.

The resulting ideological mix comprises three main components: virulent anti-immigrant animus, ignorant anti-trade rhetoric, and extreme anti-government sentiment. Taken separately, any one of these would be damaging. Together, they would deal a major blow to US and global prosperity, while also weakening national and international security.

Without question, Trump is the most anti-immigrant presidential candidate the US has seen in modern times. His first idea and overriding catchphrase is to “build a wall” along the country’s southern border, which would supposedly keep out Mexican and other Latin immigrants. He also wants to deport 11 million people and keep out all Muslims.

This is a recipe for a police state – checking identities, raiding people’s houses, and encouraging neighbors to inform on one another. It is also fundamentally anti-American, in the sense of undermining everything that the country has achieved. The US is a nation of immigrants – the best in the world at integrating new arrivals. After one generation in the country, no one cares where your family came from.

Trump – and those who bring him to power – would throw all of this out of the window. The associated social disruption would by itself cause not just an economic slowdown, but a sustained decline in GDP and incomes.