models and a controller question

SoldierCoderControllerQuestion

Ok, users should get a list of campaigns (to add or withdraw support 
to/from whether or not they support it now.  But I also want to to 
show if they are supporting it.  

CampaignSupporters will hold information about which users 
currently support which campaigns.  But how do i get list 
of all campaigns so logged in user can choose which they'd 
like to support?


class Campaign < ActiveRecord::Base
  has_many  :campaign_supporters
  has_many  :users, :through => :campaign_supporters
end

class User < ActiveRecord::Base
  has_many :campaign_supporters
  has_many :campaigns, :through => :campaign_supporters
end

class CampaignSupporter < ActiveRecord::Base
  belongs_to  :campaign
  belongs_to  :user
end