Gosh. That was some blue touchpaper.
Sorry if I have offended any sensibilities it was just a question tossed into the ring for a bit of (light?) debate.
One thing that comes across from these remarkably homogeneous replies however, is the failure to differentiate between "politicians" and the Monarch. You assume a huge gulf between the poor old Queen (Gawd Bless 'er etc) as she valiantly carries on working her fingers to the bone in line of duty (and you thought the nurses had it tough) and the assortment of weasel low-life in ****ehall and Westminster.
There is NO difference. That's my point.
The oath is a smokescreen that gives the impression of allegiance to the person of the Monarch, but that same Monarch is but a rubber stamp that will happily sign into law every bit of Lib-Lab-Con insanity that passes across her desk without a moments thought for the consequences.
By making such a solemn act as an Oath Of Allegiance more relevant, for example to a Written Constitution that would protect our freedoms rather than hand them over to the EU or allow a criminal rodent like Blair to take us to war in Iraq on a pack of lies, surely that would be a force for good.
The oath would be sworn to defend that Constitution and prevent examples like the above from happening again. What's wrong with that?