This will skip your validations:
vote.save(:validate => false)
more info here
To skipping your callbacks and validations, you can use, update_column v(3.1), or update_all
vote = Vote.first
vote.update_column(:subject, 'CallBacks')
Aparentlly this only works with ActiveRecord 3.1
Or:
Vote.where('id = ?', YourID).update_all(:subject => 'CallBacks')
In the end you have also i finally option and this will skip everthing:
execute "UPDATE votes SET subject = 'CallBacks' WHERE id = YourID"
OK the last one it's not so pretty.