A week is a long time in politics. So goes the cliche. When it comes to US politics in the era of Donald Trump, that cliche has more truth than usual.

Last Tuesday, and quite by coincidence, legal proceedings against two of Trump's closest former associates - Michael Cohen and Paul Manafort - came to a head. The claims of the former that the president broke the law, which are much more significant than the conviction of the latter for fraud, brought the already heightened coverage of the Trump presidency to fever pitch.

Legal scholars and historians have been out in force explaining how the US system deals with law-breaking presidents and past impeachment precedents. But this may all end up being just like other happenings that would have ended the political careers of any other US politician but which Trump can sail through.

As is the case in France, which also has a presidential system, US presidents are immune from prosecution while in office for all intents and purposes. But that does not mean Trump can shoot someone on New York's Fifth Avenue and get away with it, as he said two weeks ago.

As anyone who recalls the events around the impeachment of Bill Clinton exactly 20 years ago might know, US presidents are held to account not by the judiciary, but by the legislature. If a simple majority in the House of Representatives votes for impeachment the Senate then decides whether he (or she) is guilty. Senators can remove a sitting president if two thirds of them back that course of action. In Clinton's case, the House impeached but the Senate acquitted.

With a Republican majority in the Senate, and every expectation that they will retain their majority in November's mid-term elections, it would take almost half of the party's senators to vote against Trump if the two thirds threshold is to be reached.

Just how unlikely that is was brought into focus last Monday before the court proceedings against Cohen and Manafort exploded. At an event hosted by the Institute of International and European Affairs (where I work) I had a wide-ranging discussion with Sean Spicer, the current administration's first White House press secretary. Testament to the scale of the interest in the Trump phenomenon, it was one of the best-attended events in the institute's near three-decade history.

Spicer has worked in the machinery of the Republican Party for a quarter of a century. As is the case in Ireland and elsewhere, professional backroom people in politics understand what makes their supporters tick better than anyone.

Although it's not clear that Spicer, or indeed anyone, really understands what makes Trump so utterly unique, it is increasingly clear he enjoys a loyalty among his supporters that was previously thought impossible in a country that has long been cynical about politics and politicians. No matter what the US president does, says or is accused of, those who are favourable to him don't seem to change their views of him.

As Spicer pointed out, his opinion poll ratings among his party's supporters remain stratospheric compared with previous presidents and only George W Bush in the immediate aftermath of 9/11 has scored higher. And as anyone who has observed how political parties function will know, doing well in elections and enjoying strong support from the grassroots puts leaders in a near invulnerable position vis-a-vis internal rivals.

One factor that Spicer stressed in explaining the intense loyalty Trump enjoys is a sense among many Republicans that until he came along they were dismissed and disrespected not just by their political rivals, but by their own party too.

Modern voters are not deferential as their grandparents might have been and they don't take kindly to being ignored and disrespected by politicians. Trump gives these Republicans and Republican-leaners a voice. It says something quite profound about a mature democracy when 45pc of people - his current approval rating - feel that a ranting egomaniac is the voice that represents and respects them.

Another notable point made by the ex-White House spokesman last Monday was on the implications of November's mid-term elections for Trump. He conceded that the Republicans could lose the House of Representatives, but that the president's chances of re-election in 2020 would be bolstered whether or not that happened.

The logic is as follows. If the status quo is maintained, Trump will be able to continue to push through laws that please his supporters and allow him to portray himself as the guy who gets things done. If, on the other hand, the Democrats take the lower house and block legislation, Trump will take to his Twitter bully pulpit and berate them for causing gridlock. Although it is moot that both possible outcomes in November will improve the incumbent's chances of re-election in two years' time, Trump's defiance of what were believed to be immutable laws of American politics means it can't be ruled out.

Given the importance of trade with the US for Ireland and Spicer's own role in the US's de facto trade ministry during the presidency of George W Bush, I was particularly interested to glean any insights into where Trump's aggressive trade policy was heading.

As background it is worth noting that one of Trump's long-standing views, dating back to the 1980s, is that the US has been outmanoeuvred and out-negotiated in its relations with other countries on trade. This is based on the (misconceived) view that if a country sells more goods to America than vice versa something must be awry. To see why this is misconceived one only needs to consider Ireland. It has a massive and long-standing trade deficit with Britain, but nobody claims it is because of some structural unfairness.

Spicer repeatedly referred to the US's trade relations with other countries as being "unfair", and as being perceived to be unfair by Americans. More generally, he observed that the positions of both US parties on trade had not moved over time to reflect less favourable public opinion.

The US has been the anchor country in building and maintaining the rules and structures which facilitate international trade. Trump does not believe the existing order serves American interests. If he goes down the path he has taken of tariffs and trade wars it is not at all clear that the existing order can survive.

If it doesn't, that would have profound consequences for the transatlantic economic relationship, among many other things. Ireland's economic model is based on being an important hub in the North Atlantic economy. This model may not be sustainable if the US and American public opinion continue in the direction they are both going.

The discussion between Sean Spicer and Dan O'Brien can be viewed here https://www.iiea.com/geopolitics/the-evolution-of-american-conservatism-the-presidency-of-donald-trump-and-the-implications-for-us-foreign-policy/

Sunday Independent