I have seen many petitions asking the same thing, each with several thousand votes. This makes each petition less effective, reducing the power of each signature.
The Executive Branch of the US should hire website administrators/moderators to offer petition "owners" the opportunity to merge petitions so as to reduce redundancy, increase diversity, create jobs.
A proposed solution could include moderators looking through the website, and emailing both users offering a merge. If both accept, the merge would occur and both users would be listed as owners/starters. Otherwise, the petitions would remain separate.