You may need to add removed constituents to a group, specifically if you are trying to have support re-activate those constituents. You can add the constituent to a group in this way:
  1. Navigate to Constituent360 > Constituents
  2. Type the name of the constituent
  3. Mark the checkbox "Include removed (inactive) constituents in search results.'"
  4. Click Find
  5. Click View on the record
  6. Select the Groups tab
  7. Click the Edit Group Membership link towards the middle of the page
  8. Search for the group name
  9. Click on the group name under the Search Results column
  10. You should see the group name also appear under the Selected column
  11. Click Save