Why America could (probably) survive a President Trump

For sure, Trump is like no politician in recent American history. For now, I don't necessarily expect him to win — his supporters might be enthusiastic, but he could be even more effective at getting his opponents out to vote against him.

Still, there are routes by which he could win, particularly if Democrats fail to come out for Hillary Clinton as expected.

Even if that doesn't happen, the Trump phenomenon is part of a much wider — perhaps even global — political trend. That could have implications well beyond the United States.

Indeed, America is one of the few countries in the world that could actually withstand a Trump-type presidency.

For all his rhetoric, a President Trump would, like all other occupants of the Oval Office, find himself constrained by the Constitution, judiciary and Congress. Even if the Republicans do retain control of the House and Senate, many members of Congress are already voicing their opposition. And if a Trump presidency proves as contentious as many expect, it could easily deliver the Democrats control of Congress in 2018.

Earlier this month, I took a shot at imagining in more detail what future historians might make of a Trump presidency. My conclusion was that he might last one term, achieve much less than he initially expected and quite possibly exert considerable energy on minor changes to real estate laws.

That doesn't mean he wouldn't have an effect, particularly on perceptions of the United States in the rest of the world. The optics of his rhetoric on Islam is already playing badly in the Middle East. As president, that — particularly if tied to more indiscriminate military action — could prove disastrous.

Still, overall he would be restrained. And, just like the current incumbent of the White House, would probably leave largely frustrated by what he had failed to do.

While Trump is a unique political creature, the forces he is riding go much deeper and wider — and have been growing for a while. Ultimately, what he is really taking on is much deeper societal frustration — particularly with political elites on both sides. His strength is that he looks authentic, and he has successfully used both social and traditional media to persuade huge swathes of supporters that he is the candidate most like them and most in tune with their — not always politically correct — instincts.

On the left in the United States, we have simultaneously seen Bernie Sanders harnessing some of the same frustrations to mount a credible challenge to Hillary Clinton. In Europe, we've seen the rise of both non-traditional left and right parties.

We've also seen unexpectedly left-wing leaders in particular — for example, Britain's opposition Labour leader Jeremy Corbyn — seize control of what had been much more moderate mainstream political parties.

In most cases, those elected so far have remained relatively committed to operating within established political systems. Some of the more radical groups — such as Marine Le Pen's far right in France — have performed worse than many expected. (France is, after all, a country that endured Nazi occupation in relatively recent history.)

That may not always be the case, though — none of these frustrations are going away and in Europe, the migrant crisis may yet fuel a further move either to the extremes or to more generic authoritarianism. The chaos of the 1990s in Russia, after all, helped set the scene for the rise of Vladimir Putin.

Already, some Europe experts talk of a rise in authoritarianism, particularly in the communist states of the former Eastern Bloc. Hungary has seen the rise of Viktor Orban and his far-right Jobbik party. Poland has seen something similar, while this month's elections in Slovakia saw a much-better-than-expected performance by the very far right.

Like Trump, these leaders are invariably nationalist, more isolationist, anti-globalization in general and anti-migrant in particular.

That's when political systems become really important. In the United Kingdom, the parliamentary system usually keeps the fringe parties — such as the anti-EU UK Independence Party — almost entirely sidelined from elected office. (Although the rise of the Scottish National Party, which now controls most parliamentary seats in Scotland, is probably another sign of this trend.)

In Germany, however, a much more proportional representation-based system means that a radical Trump-type figure could make himself a kingmaker in German politics with a small share of votes, say 25 percent. In the 1930s, Adolf Hitler and the Nazis were able to use that kind of platform to take control of the entire country.

The United States isn't Weimar Germany, and Donald Trump isn't Hitler (despite the words of comedian Louis C.K.) But it says a lot about the United States' founders and system of government that it could likely survive a politician worse than The Donald.