Whatever we feel about Trump, his Irish visit is a necessary evil in the world of realpolitik
It's tempting to speculate that US President Donald Trump has promised to make space in his schedule for a trip to Ireland in the same spirit that he said he'd build a wall between the US and Mexico, forcing the Mexicans to pay for it.
In other words, no need to worry about shampooing the red carpet and ordering bulk supplies of stars and stripes bunting just yet.
But if he lasts a four-year term, we can be sure he'll call in the Taoiseach's invitation. Not because he's taking an interest in his "new friend" Enda's little country. Not because he wants to inspect his Doonbeg golf resort investment. But because a state visit will help to secure the Irish-American vote.
Touchy about his popularity, or lack of it, Mr Trump will focus on re-election sooner than his aides do. He'll be banking on images of him glad-handing in Ireland to soften up the Irish-American electorate back home.
"For the United States, Ireland carries a blood link," former US president Barack Obama has observed. There will be street protests, naturally, but Mr Trump will look the other way.
Consequently, we may resign ourselves to Air Force One pointing eastwards, to deposit the so-called leader of the free world on the national doorstep sooner or later.
In tandem, we can expect a wave of acrimony. Public demonstrations are a given, invitations to meet him will be refused (and not politely), while rancorous debate will flow. Inevitably, security will be tight as a drum, and gardaí can anticipate an overtime bonanza - it's an ill wind, etc.
Is the prospect of a Mr Trump State visit a disaster? Hardly. It's a necessary evil in the world of realpolitik. Make no mistake, his racism, misogyny and homophobia are dangerous and repellent. But he is the democratically elected leader of the US and his office must be respected.
Shutting Ireland's door in his face would cause huge diplomatic offence. Other world leaders will adopt the same pragmatic approach, irrespective of their private views about him. Also, American business investment matters to Ireland. Companies such as Apple, Dell, Google, Facebook and Pfizer generate employment here: some 140,000 people have jobs with US multinationals. The spin-off in indirect employment is an additional benefit, with accountancy, cleaning, office equipment, electricity, telecoms and other services supplied to the multinationals.
Citizens aren't obliged to give Mr Trump a céad míle fáilte, however. Indeed, more than a million signatures have been collected for a petition in Britain demanding the withdrawal of Queen Elizabeth's invitation to the US leader. Clearly, many of our neighbours have reservations about showing hospitality to him for the same reasons that a number of Irish people do.
But we're under no obligation to line the streets, waving flags, when he comes calling. People are free either to ignore the visit, or to participate in protests. There is a 50-year tradition of serving US presidents visiting Ireland, and a practice that's almost as long of citizens expressing disagreement with their policies.
President George W Bush spent just 16 hours here in 2004, along with an army of security personnel, attending an EU-US summit. Thousands of protesters marked his stay by taking to the streets to voice their opposition to American torture policies at Guantanamo Bay.
President Ronald Reagan's 1984 visit sparked heated protests about his foreign policy in Central America. Politicians walked out when he addressed the joint Houses of the Oireachtas; Cardinal Tómas Ó Fiaich and various bishops, including Eamonn Casey, turned down invitations to official events; academics disassociated themselves from the NUI's decision to honour him. President Michael D Higgins, then a senator, took part in protests.
As for president Richard Nixon, his limousine was pelted with eggs as the motorcade drove through Dublin when he visited in 1970 at the height of the Vietnam War.
It's a safe bet that Mr Trump's visit will be a diplomatic headache for whichever government holds office.
Nevertheless, the Taoiseach had little choice but to extend the invitation. Galling though it is to welcome Donald Trump the man, it is essential to do it for Donald Trump the head of state. It's called taking care of business.
The proposed trip has practical value in maintaining the tradition of state visits by serving presidents started by John F Kennedy in 1963. Not all came, but most did. It's hard to see any downside for Ireland in continuing that habit.
Some might say Enda wasn't obliged to invite Mr Trump - he could have claimed he was about to leave office and suggested the White House should discuss it with his successor. But that would have undermined the Taoiseach's mission in the US this week.
Besides, there he was with Potus, head of the world's largest economy, enjoying a slice of access blocked into the calendar. How could he refuse to reciprocate if Mr Trump let it be known he fancied an invitation?
That annual set-piece surrounding a bowl of shamrock's delivery affords Ireland the possibility - maybe remote but it exists - of influencing US policy. Mr Trump doesn't appear to have especially talented aides, and some of his advisers are promoting a questionable agenda - chief among them Steve Bannon. Therefore, interaction with the president gains heightened significance.
Throughout his visit, the Taoiseach pressed home the message that the EU is a positive institution, an antidote to Nigel Farage's negative interpretation ringing in Mr Trump's ears. In addition, he raised the question of illegal immigrants before the president publicly. Some would prefer him to have said more. Even so, Enda used his St Patrick's festival opportunity to make some efforts to speak truth to power.
"I really love Ireland, I'll be there absolutely," said Mr Trump, when questioned by reporters about whether he intended to visit. Events may overtake him, of course. But if he does drop in, we should seize the chance to engage with him. After all, it's impossible to change someone's mind by refusing to talk to them.
Mr Trump is a reality we are obliged to connect with, like it or not. Who knows what might spring from it? Despite sustained opposition to the visit by Ronald Reagan, he surprised people by mentioning Northern Ireland every day he was here - helping to push the need for a solution higher up the agenda.