Ministers are clearly punting that if affected pupils are in their new school at the beginning of 2014 then they (or more importantly vote-wise their parents) will have adjusted by the time the election rolls around later in the year.
Weighing on John Key and his colleagues' minds is the need to buttress National's hold on the the city which applauded the party for its handling of the post-quake recovery by increasing National's party vote in Christchurch at the last election from just under 90,000 to just over 95,000.
With Labour's share in spectacular decline - from around 97,000 in 2005 to just over 51,000 at the last election - National won the party vote in the supposed Labour fortresses of Christchurch Central and Christchurch East.
To hold onto power after the next general election, National's strategists somehow have to stop those cross-over voters who have no real allegiance to their party shifting back to Labour.
The school rationalisation exercise was always going to jeopardise National's retention of that "soft" vote. Much of the damage from the quakes was in east Christchurch.
Thus many of the affected schools are in those two seats.
Hence yesterday's drastic revision of the numbers.
While the media will focus on the shock and dismay surrounding the closures, many parents and teachers will have been mightily relieved last night.
They will not thank Parata, despite her putting in a much more polished performance yesterday.
But what National is really hoping is that those voters - and the many more beyond Christchurch - will recognise the message that National is a Government which still listens.