It is the sad fate of the constitution to be only a very marginal interest, especially taken as part of an issue as exciting and all-encompassing as Brexit.

Thus today’s news that David Lidington has offered the devolved administration a ‘gamut’ of post-Brexit powers will probably be treated as a second-order story, another embarrassing climbdown for an administration well-practised in retreat.

But although constitutional issues move at a glacial pace, so too do they have a glacier-like ability to transform the political landscape. Future governments will likely come to rue this administration’s inability, or unwillingness, to carry Claus 11 of the Withdrawal Bill over the line.

You can read the full-fat case for the clause, by one of its architects, in this paper for These Islands. I also provided an outline of the arguments back in November. They are no less true now than they were then, so I won’t repeat them at length here.

Rather, it’s worth looking ahead to consider the sort of trouble this capitulation – and for all that the devolved assemblies are drawing it out, a capitulation is what it is – may cause future prime ministers.

Most immediately, this demonstrates that the weight of inertia behind devolution remains so strong that it can carry the day even when it’s arguments are – as suggestions of a Westminster ‘power grab’ are – total nonsense. For a certain, powerful section of the devolutionary governing class, the demand for “more powers” is intellectual muscle memory and the centre has developed no meaningful capacity to resist it.

Second, by retreating the Government has conceded the idea that there is something fundamentally illegitimate about governing from Westminster. The idea that it is unacceptable for powers exercised by Brussels to be exercised by London is inherently anti-British, requiring as it does the belief that there is something particularly illlegitimate about UK-level governance.

It is a strange unionism which demands that Britain, an actual country, be less well-integrated than the EU, a inter-state arrangement. But now that ministers have conceded the idea that even UK-wide policy should not be ‘imposed’ by our UK-wide legislature, expect to see this precedent levelled against Westminster time and again.

This is especially disappointing given that, before the election, Theresa May really seemed to have twigged that unionists actually needed to defend Westminster and its role in governing the whole of the country. But the loss of her majority, and certain key figures who had been at the heart of the Government’s unionism, seems to have done for that.

Third, we have the actual powers themselves. These were passed up to Brussels because it was believed that harmonising them was necessary for the smooth functioning of a single market. The idea that most of them can simply be set at the sub-state level is implausible, especially if advocated by people who otherwise support ongoing membership of the single market and thus the powers staying where they are.

This sort of unwieldy confederalism would be a sub-optimal way to organise a relatively small country such as ours even before the inveterate tendency of devolved politicians to grandstand against Westminster were taken into account. Throw in one or more devolved administrations run by parties dedicated to breaking up the Union and you have a recipe for deep dysfunction.

Devocrats like to talk of a ‘constitutional crisis’ if their demands had not been met, which makes it sound as is the Government didn’t have a choice in the matter, but that’s as thin as their ‘power grab’ line. The mechanism by which Holyrood and Cardiff Bay give ‘consent’ to reserved legislation is a courtesy, and refusal has no constitutional consequences whatsoever.

Facing down Nicola Sturgeon, Carwyn Jones and Ruth Davidson may have had political consequences, perhaps very challenging ones, but a political crisis is not the same thing as a constitutional one and the Government’s retreat must be weighed against the threat it actually faced.

The Prime Minister is setting a course for stormy constitutional waters. Perhaps a future, bolder administration – one with rather less on its plate – will find a way to mitigate or even roll back the most damaging of these concessions. History doesn’t offer much hope of that, however.