I've just read a book on the Magna Carta, and am surprised that people still give it as much relevance as they do. The 1215 version was basically ignored by King John, and was rewritten and reissued tens of times in the years afterwards.

http://www.rugbyadvertiser.co.uk/news/local-news/magna-carta-at-800-everything-you-need-to-know-1-6798715

There's to be 'mock trial' about the Magna Carter about now. Were the Barons guilty of treason?

Barons face trial

It'll be interesting to follow, but I can guess the outcome!

The point about the Magna Carta is that it granted nothing and was simply a balancing act between the early medieval monarchy and the leading members of the aristocracy.
It was re-published so many times because it needed to be checked for the detail to make sure the monarch in particular was abiding by it - usually not.
It has an importance, but I wouldn't raise hymns of praise to it, because again, it granted nothing and merely acknowledged that John was behaving badly by the accepted norms.
It needs to be stressed that the freedoms that we have in this country were NOT granted by any body or thing and certainly not by parliament and developed slowly from Saxon times onwards. The Left and the Liberal mafia that run this country love documents like the Magna Carta, because they love to see statements in writing about what you can and you can't do. Oddly enough, with the exception of king John, what might be called ordinary people, that is you and I, faired much better under the monarchs who were keen to protect their subjects and particularly the poor against aggressive attacks on them by the aristocracy and the upper middle classes in this country. For all his faults, king Charles 1st. protected and preserved the poor better than that fascist Cromwell with all his lawyers and middle class followers, keen to despoil the ordinary people of this country, a process which continues even today.