In 1829, Andrew Jackson entered the White House after a handsome electoral victory. He thereupon removed 919 government officials – about 10 per cent of the administration – so he could fulfill numerous promises made to people during the election campaign. And so began the "spoils" or patronage system in US politics, which has ebbed and flowed ever since and is now flowing "bigly".

Jackson had other similarities with Donald Trump. He was very much an "America-first" president. The previous six presidents were more internationally inclined. Jackson also saw himself as "the direct representative of the common man" and very much anti-establishment. He was also in favour of abolishing the electoral college, just like Trump – at least until the 2016 election night.

Some of this history can help explain, if not the actions of Trump himself, at least historical trends behind the reasons people voted for him.

Jackson founded the Democratic Party, which has obviously evolved for the better since, but it shows that party labels are not always helpful in understanding presidential positioning. Remember, Abraham Lincoln was a Republican.

Nor are the labels "left" and "right" especially helpful. It's difficult to pin either label on Trump. "Radical", "conservative" and "liberal" are also not very helpful.

Somewhat more helpful is a president's attitude to the outside world – whether he (and they have all been men) is an isolationist, on one hand, or an international engager, on the other.

The first six presidents were international engagers insofar as the times allowed. They thought America had something unique to offer the world through the declaration of independence's words "that all men are created equal, that they are endowed by their creator with certain unalienable rights, that among these are life, liberty and the pursuit of happiness". It wasn't just Americans but "all men". (Women and slaves were to get that equality later, at least theoretically.)

The first six presidents hoped that this first republican constitution with checks and balances and a bill of rights would be an example to the world. Jackson changed that, at least for a fair while.

Later, Lincoln took the world view despite being embroiled in the Civil War. At Gettysburg, he implored that "government of the people, by the people, for the people, shall not perish from the earth". Not just from America, note, but from the whole earth.

But isolationism has always had substantial if not majority support in the United States. The US refused to join World War I, which it saw as a European war, until 1917 and even then it was opposed by many voters. After the war, Democrat president Woodrow Wilson, perhaps the most internationalist of all US presidents, wanted the US to lead the decolonisation, self-determination and democratisation of the world with his "14 points" and the creation of the League of Nations.

But again simmering isolationism came to the fore. Republicans in the Senate blocked the Treaty of Versailles and the League of Nations. Isolationism and Wilson's ill health resulted in the Democrats not nominating him for another term.

For the next 12 years, the US was presided over by three almost Trump-like businessmen presidents: Warren Harding, Calvin Coolidge and Herbert Hoover.

Coolidge said: "The business of America is business." Just the sort of thing Trump would say (or tweet). The three Republicans eschewed free trade and international cooperation and were overconfident almost to Trumpian levels.

That and their protectionism led to the Great Depression. Because the US was not in the League of Nations nor a party to Versailles, it had virtually no international influence in engaging with Germany and Japan in a way that would have lifted them out of the wreck of World War I with dignity and prosperity, in a way that the more internationally engaged Harry Truman did after World War II.

When the wealthiest nation withdraws from international engagement, history shows that depression and war become more likely. Part of that disengagement, of course, was refusal to helps Jews escaping Nazi Germany. Xenophobia and stereotyping go hand-in-hand with isolationism.

From 1933 to 1952, presidents Franklin Roosevelt and Harry Truman restored internationalism and help establish the new world order with world economic institutions. Dwight Eisenhower (the best Republican president since Lincoln) at least allowed it to continue.

Then we had a period through which the US was very much internationally engaged, but not benignly, rather as a military interventionist. Communism and violence in the Middle East, first threatening US oil and then civilian life in the US, were about the only things that kept those Republicans who occupied the White House since Johnson internationally engaged. Without them, Trump-style isolationism would have prevailed in those years, too.

Look at the attitude of George W. Bush to foreign affairs before the World Trade Centre attack, for example.

Isolationism and withdrawal runs deep in the US. The US has still not signed the UN treaty on the law of the sea. Nor does it recognise the International Criminal Court. Even Democrat president Bill Clinton rejected help in Rwanda and delayed or avoided intervention in Bosnia and Kosovo as far as possible. Democrat president Barack Obama avoided as much as possible intervention in Libya and Syria. This was not just fear of Vietnam-type quagmires, but a concern that many, if not most, Americans, most of the time, are isolationist and deeply suspicious of foreign engagement, whether militarily, in trade or in social cooperation.

With varying degrees of consistency, Trump has espoused non-intervention in foreign conflicts; withdrawal from, or at least ambivalence to, multi-lateral military alliances; opposition to a range of other treaties; and a deep suspicion of foreign aid. America first.

So international cooperation and collaboration; adherence and submission to international law; advocacy of democracy and liberty and generous foreign aid are not permanent features of the American political landscape, nor permanent desires of a majority of American voters.

For many or most Americans, American exceptionalism means putting America first and saying America is greatest. It is not, as many liberal democrats desire, the expression of the idea that the American Revolution was the first to put into practice universal values which are worth upholding universally.

So don't imagine that voter support for Trump is somehow an aberration, even if the man they voted for is. Isolationist thinking has been a powerful force throughout American presidential voting history, maybe not with the same chaotic inconsistency as with Trump, but there nonetheless, and as dangerous – if the Harding, Coolidge, Hoover period is any judge.

crispinhull.com.au