Hi mad dog wilful,
I thought it was the genius of Runnymede to say that the monarch is subject to the law (alongside the notion of habeas corpus which is the foundation of the freedom of the individual). The abstract crown is distinct from the corporeal king.
We topped a chap wearing a crown to show you what this means. Sometimes you may want to get rid of the top guy and open up a vacancy for the title. This is what the regicides said:
"Having by our late labours and hazards made it appear to the world at how high a rate we value our just freedom, and God having so far owned our cause as to deliver the enemies thereof into our hands, we do now hold ourselves bound in mutual duty to each other to take the best care we can for the future to avoid both the danger of returning into a slavish condition and the chargeable remedy of another war. For as it cannot be imagined that so many of our countrymen would have opposed us in this quarrel if they had understood their own good, so may we safely promise to ourselves that when our common rights and liberties shall be cleared, their endeavours will be disappointed that seek to make themselves our masters. Since therefore our former oppressions and scarce-yet-ended troubles have been occasioned either by want of frequent national meetings in council or by rendering those meetings ineffectual, we are fully agreed and resolved to provide that hereafter our representatives be neither left to an uncertainty for the time, nor made useless to the ends for which they are intended." - An Agreement of the [English] People - 1647
Isn't that also what your framers wanted and why they separated powers? The people are the tops. That piece of parchment (and the other one declaring your independence) defines your sovereignty.
One of the purposes of the constitution was to make it possible to hamstring a populist. We are all subject to the rule of law.
Easier said than done of course.