I don't think it would be that difficult for him to "destroy" it in the sense of making it no longer a practical method of imprisonment. All he would have to do is start disseminating knowledge of the true patronus charm, and using dementors as the primary guards of a prison would cease to be viable.
People could still be tormented by the dementors when their wands are taken away, and left unable to escape, but using dementors as a torture device which itself needs to be guarded from anyone who might decide to obliterate them all is probably a lot less politically viable.
In terms of retaining political advantage, this may not be the best method available to him, but it may be the easiest.
Attempting to coerce the dementors directly and break their pact with the Ministry retains more power, as does taking away everyone else's ability to use patronuses, leaving himself in control of the dementors, but both are vulnerable to interventions such as, say, kidnapping him and crucioing him until he surrenders.
Harry doesn't need his wand. I think that's only because he mastered his Hallow.
This is a new thread to discuss Eliezer Yudkowsky’s Harry Potter and the Methods of Rationality and anything related to it. This thread is intended for discussing chapter 81, which should be published later today. The previous thread passed 400 comments as of the time of this writing, so it will pass 500 comments soon after the next chapter is posted, if not before. I suggest refraining from commenting here until chapter 81 is posted; comment in the 12th thread until you read chapter 81. After chapter 81 is posted, I suggest all discussion of previous guesses be kept here, with links to comments in the previous thread.
There is now a site dedicated to the story at hpmor.com, which is now the place to go to find the authors notes and all sorts of other goodies. AdeleneDawner has kept an archive of Author’s Notes. (This goes up to the notes for chapter 76, and is now not updating. The authors notes from chapter 77 onwards are on hpmor.com.) When posted, chapter 81 should appear here.
The first 5 discussion threads are on the main page under the harry_potter tag. Threads 6 and on (including this one) are in the discussion section using its separate tag system. Also: one, two, three, four, five, six, seven, eight,nine, ten, eleven, twelve.
As a reminder, it’s often useful to start your comment by indicating which chapter you are commenting on.
Spoiler Warning: this thread is full of spoilers. With few exceptions, spoilers for MOR and canon are fair game to post, without warning or rot13. More specifically: