In law, sedition is defined as any overt conduct, such as speech and/or organization, that is deemed to tend toward insurrection against the established order. The definition of sedition includes subversion of the United States constitution and resistance to lawful authority.
Note that to be convicted of Sedition, a person does NOT need to advocate direct and open violence against the laws.
The act of signing one or more of the petitions clearly meets the legal description as set forth above. The Obama administration is asked to carry out its responsibilities to the American people by prosecuting these secessionists to the full extent of the law.