Can I permanently delete a campaign?

A campaign cannot be permanently deleted from your account, but it can be Archived from the campaign's Overview tab - Pause the campaign first, and the option to Archive the campaign will appear. If you intend on creating a new campaign with the same name, you will have to change the name before Archiving. If the name isn't changed beforehand, it will remain logged as a campaign name and will prevent you from creating a duplicate.