The opening session of the epic Supreme Court hearing into whether Boris Johnson misled the Queen and broke the law when proroguing parliament did not disappoint.
Because Lord Pannick, for one of the plaintiffs Gina Miller, captured with the clinical precision of a brain surgeon quite what is at stake.
Summing up, he asked the law ladies and lords to consider that if they were to conclude there is no case for the PM to answer, a future PM might well feel licensed to suspend parliament for six months or a year, as and when MPs become bothersome, rather than “just” the five weeks Johnson has chosen to shut down parliament?
What is at stake, Pannick implied, is the role and power of the courts to prevent a PM choosing to become an elected dictator.
The difficulty, Pannick conceded, is that because what Johnson did is “unique”, there is no precise legal precedent for the judges to rely on when making their eventual ruling on Friday or Monday. They will have to consider “principle”.
And for Pannick the core principle is that in the British constitution, gloriously unwritten, the senior lawmakers are MPs and Lords, the legislature, with the PM and the executive the junior partner.
His central argument is that the PM trampled on the fundamental rights of parliament to legislate and scrutinise PM and ministers by sending them home for five weeks.
What’s more noxious, he said, was he did this at a time of huge historic importance, when MPs and Lords demonstrably wanted to hold the PM to account in parliament for the method and timing or Brexit.
Counsel for Johnson will this afternoon argue that parliament has been suspended for the wholly legitimate purpose of preparing a legislative programme to be announced in a Queen’s Speech when parliament resumes on 14 October.
But Pannick would say “pish posh” or “it don’t matter”. Because he avers that even if Johnson’s motives were honest – and many doubt that – it is the effect of the prorogation that matters. And the toxic effect, he says, is to silence and neuter MPs against their revealed wishes, and against the public interest.
Except for one thing, as pointed out by a law lord.
MPs had the opportunity, through a vote of no confidence, to throw out Johnson, before the prorogation. And they failed to seize that opportunity.
Pannick tried to dismiss MPs’ refusal to sack Johnson as not relevant to the constitutional and legal position. He may be right.
But in the court of public opinion it will matter.
Those MPs who want the Supreme Court to rule that Johnson unfairly shut them up will have to explain why if he is such a tyrant they baulked at the opportunity of throwing him out when they had the chance.
Which is a question of especial relevance for the leader of the opposition Jeremy Corbyn, whose refusal to support the trumpeted idea of a temporary government of national unity to replace Johnson killed it stone dead.
Robert Peston is ITV’s political editor. This article originally appeared on his ITV News blog