Could Snape have broken the curse on the DADA job?

Question

In the 6th chronicled year at Hogwarts, Snape is the new Defense Against the Dark Arts (DADA) teacher. Slughorn replaces him as a Potions teacher. At the end of the sixth year

Snape kills Dumbledore, per Dumbledore's request. Nobody except for Snape knows that though.

The next year

Snape replaces Albus Dumbledore as headmaster of Hogwarts.

And Amycus Carrow becomes the new Dark Arts teacher. Now, all the DADA teachers (at least the ones mentioned in the book, while HH&R were at Hogwarts) could not have been DADA teachers the next year.

1. Quirrell

   Killed.

2. Lockhart

   Memory was wiped nearly completely.

3. Lupin

   Lupin turned into a werewolf on school grounds. The incident was found out by parents of Hogwarts students, who wouldn't allow Lupin to teach there anymore.

4. Mad-Eye Moody

   Actually Barty Crouch Jr.

   Was dealt the Dementor's kiss.

5. Umbridge

   After everyone figured out that Dumbledore was telling the truth about Voldemort's return, his reputation was reinstated and therefore Umbridge was removed from Hogwarts.

The problem is that Snape could've taught DADA in what would've been HH&R's seventh year, there was nothing stopping him. If somebody else had become

Headmaster

instead, then Snape could've taught DADA two years in a row. Why would Snape not take the DADA job and break Voldemort's curse?

Feel free to edit the spoiler tags. I just wanted to be safe.

Answer 1

Snape didn't come out of being the DADA teacher any better - perhaps a bit more alive and in control of his faculties than some, but no better.

6. Had to kill his close and trusted friend (Dumbledore) for a roundabout chance of defeating the Dark Lord Voldemort, taking up his position as headmaster as a barely consolatory prize.

To say nothing of what happened to him in year 7.

His death.

Given these unfortunate events, it doesn't seem like him being in this position would affect the curse in any way.

Answer 2

I mainly believe that the jinx merely died with Voldemort.

but there are a couple other possibilities.

Voldemort could have lifted the jinx himself once he effectively gained control of Hogwarts. There really isn't much need for him to drive away his own agreed upon appointments.

It is also possible that it was broken with the placing of Amycus Carrow.

he teaches what used to be Defense Against the Dark Arts, except now it's just the Dark Arts. -The Deathly Hallows, Chapter 29: The Lost Diadem

See, the jinx was linked to the position of professor of "Defense Against The Dark Arts," which effectively ceased to exist with the appointment of Amycus Carrow.

After it was reinstated, it could have been considered a new position.

Answer 3

Taking the job for another year might not have broken the curse.

It’s unclear how the the curse on the Defense Against the Dark Arts position worked, and therefore we don’t know if someone takes the job for another year if it’ll break the curse or just sign them up for another year that’ll end in misfortune.

At that point, Snape had higher priorities than breaking the curse.

When Snape decided not to return to the Defense Against the Dark Arts post, he’d had much bigger priorities than the curse on it - he had to use his position as headmaster to keep the Death Eaters from doing too much harm to the students, and carry out the rest of Dumbledore’s orders to him regarding the Horcruxes. For his priorities, it was best he take the most powerful position at Hogwarts. He’d have more control and wouldn’t have to answer to whoever became headmaster, which would have been a (more loyal rather than being a spy) ally of the Dark Lord.

The curse broke upon the Dark Lord’s death.

There is information about how the curse on the Defense Against the Dark Arts teacher was actually broken. J.K. Rowling said in an interview that the jinx on the Defense Against the Dark Arts was broken because the Dark Lord was gone. This implies that his death was what finally broke it.

MV: Do you-- do Ron and Hermione or Harry ever return to Hogwarts in any capacity?

JKR: Well, I can well imagine Harry returning to give the odd talk on-- on Defense Against the Dark Arts. And-- I-- and, of course, the jinx is broken now because Voldemort's gone. Now they can keep a good Defense Against the Dark Arts teacher from here on in. So that aspect of the-of the wizarding education is now provided for.
_{^{- Today Show interview (July 26, 2007)}}

Answer 4

Snape promised Albus that he would do everything in his power to protect the students of the school, when it fell to him to be Voldemort's 'handler' of Hogwarts.

And Snape obviously chose to be the Headmaster, which is a position of power, and spurned the DADA post(though he always wanted it), because that would actually involve teaching, which would be a hindrance to his activities.

And that would put him in contact with the students, which might create a lot of hate and chaotic reactions.

Further, if a Death Eater were to be the Headmaster/mistress, then they might go over Snape's head to act however they wish. And that would endanger the people at Hogwarts.

That answers your (implied) question of why he wouldn't appoint someone else as Headmaster.

And the curse on the position broke clearly because of Voldemort's death. We know how the Binding Curse on Harry broke when Albus died. All curses work that way.