As as Sysadmin, the system allows you to delete campaigns. Once deleted, all ideas, comments, votes, etc. within the campaign will also be deleted from the system. This data can not be recovered.
The normal use case for deleting a campaign is usually limited to deleting campaigns that never left the "Draft" state. Because of this, the campaign MUST be in "Draft" state to be able to delete it.
Once in "Draft" state, go to campaign menu, Campaign Management/Delete Campaign to delete your campaign and all related content.
Deleting a campaign is permanent and cannot be reversed.
1) Visit the campaign you want to delete. Using the menu, click on "Campaign Management/Delete Campaign".
2) Acknowledge delete request once prompted.