What does it mean to commemorate Keble's Assize Sermon?

... we have ill-learned the lessons of our Church, if we permit our patriotism to decay, together with the protecting care of the State. 'The powers that be are ordained of God,' whether they foster the true church or no. Submission and order are still duties - Keble's Assize Sermon, 14th July 1833.

Newman may have regarded the Assize Sermon as "the start of the religious movement of 1833", but what is most striking about the sermon is how it is an expression of - in the terms used by Nockles - "Orthodox [i.e. high church] political theology 1760-1833".  As Keble himself noted, the setting of the sermon embodied this:

The very solemnity of this day may remind them, even more than others, of the close amity which must ever subsist between equal justice and pure religion; Apostolical religion, more especially, in proportion to her superior truth and exactness. It is an amity, made still more sacred, if possible, in the case of the Church and Law of England, by historical recollections, associations, and precedents, of the most engaging and ennobling cast.

Nor did Keble's quite conventional Orthodox political theology disappear with the start of the Tractarian movement.  Nockles points to an 1855 Accession Day sermon in which Keble, "in the spirit of Hooker", expounded a "sacral royalism" in common with "his High Church predecessors".

It is not only in matters of political theology that we see a quite traditional expression of the pre-1833 High Church tradition in Keble.  A weekly early Communion was only introduced in Keble's parish of Hursely in 1848 but this, as Mather demonstrated, was hardly unknown to the High Church tradition of Georgian England.  And while there is no doubt, as Nockles shows, that Keble's Eucharistic theology was in this time developing in a manner diverging from the pre-1833 High Church tradition, the practice in his parish was remarkably similar to that tradition.  Indeed, as late as 1864, Keble - after the manner of the traditional High Church parson - was resisting episcopal advice suggesting there was no need for Ante-Communion to follow Mattins: 

I am afraid if I were to adopt the Bishop's plan here, that old Mrs.--, who cannot come to early Communion, would miss the Commandments and Epistle and Gospel on the Sundays when there is not a late celebration.

Even though his eucharistic theology was at this time moving significantly apart from High Church thought, George Herring's study states that Keble on reading Wilberforce's 1853 work on the Eucharist, with its 'advanced' doctrine of the real presence, "expressed his own profound hesitation in accepting such terminology".

Similarly, Herring notes that Keble, with the other early Tractarian leaders, was "deeply suspicious" of ritualism:

What the Tractarians of the earlier period sought to achieve was a ceremonial that was explicitly Anglican, derived from the Prayer Book, the Canons of 1603, and precedent such as the Laudians of the seventeenth century; a ceremonial that was intended to be adopted by all Anglicans irrespective of theological viewpoint or party. They most certainly did not look to pre-Reformation usages for their authority.

So when the anniversary of the National Apostasy sermon is commemorated, when Keble's witness is joyfully commemorated, what is it that is being celebrated?  A case can surely be made that Keble - in his political theology, in his liturgical and sacramental practice - stood in significantly greater continuity with the pre-1833 High Church tradition than with the Ritualism and advanced Anglo-Catholicism which eventually emerged from Tractarianism.  To commemorate the Assize Sermon of 14th July, then, surely is not to celebrate the Ritualism of which Keble disapproved nor the advanced Anglo-Catholicism which played no part in the life of the parish of Hursley, but is, rather, to celebrate a High Church parson in his surplice, ministering in a manner much more recognisable to his forebears than to those who claim to be his successors.