There has been a political crisis since the day Donald Trump won the White House, on that extraordinary evening of November 8, 2016. The crisis was partly caused by that famous quirk of the Electoral College that allowed him to win the Presidency with three million fewer votes than his opponent.
But the sense of “system failure” was also generated by a Washington Establishment that felt Trump was dangerously ill-equipped to govern.
Now there is something new, and very different, in the air. Not just a political crisis. But a moral emergency. A sense that the very values of America are in immediate jeopardy.
Look at today’s New York front pages:
The policy of enforced separation of families is being widely seen - by Democrats and Republicans, by almost everyone except the core of Trump’s anti-immigrant base - as a disgrace.
What’s happening is clear: Undocumented migrant families are entering the United States and are being intercepted by border agents.
The adults are being processed in the adult court system. The children are therefore forcibly separated from their mothers and fathers and are held in detention facilities.
It is in these overcrowded areas that have created the images - and the audio recordings - that are currently shocking America and the rest of the world.
Trump and his hard-line advisers are seeing this not as amoral issue but as a question of enforcing existing laws.
It is undoubtedly true - though Democrats skate over this - that the Obama Administration was also engaged in harsh and insensitive mass deportations of immigrant families.
But what’s happened now is that the pre-existing political crisis has merged with this fresh moral outrage.
Combine it with the severe legal challenges the President will shortly face when the Robert Mueller investigation comes to a climax and, well, we can see why this is going to be a long, hot - and possibly defining - summer for the White House.
The question being asked across America today is one that has been quietly posed since the day Trump won office. Except now it’s a cry of the many, not a whisper of the partisans:
Is this Presidency sustainable, and at what cost to US values?