This is a silly and reductive lens that libertarians often apply. Look at the specific examples cited in the article:

    > the Arkansas Times [...] was asked to sign [a no-boycott certification] in order to renew its advertising contract with a state technical college.
    > A teacher in Kansas was told that she could not participate in the state’s teacher-training program because she refused to sign the anti-boycott form
    > A lawyer in Arizona was told that he could not be paid for his work on behalf of incarcerated people because he refused to sign the certification
    > a child speech pathologist in Texas lost her contract with a local school district because she refused to sign.
    > One town in Texas even briefly required victims of Hurricane Harvey to sign the anti-boycott certification as a condition of receiving disaster relief funds.

It's a grotesque distortion to frame this case as involving the rights of citizens to contract with their state government and I'm certain you know it.