From _In the Interest of Children_, R. Mnookin (Ed.), Franklin E.
Zimring and Rayman L.  Solomon (Contrib. Authors):

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On January 22, 1975, The United States Supreme Court issued its 
decision in _Goss v. Lopez_ [footnote reference - "Goss v. Lopez, 419
U.S. 565 (1975)]. By a five-four vote the Court affirmed the decision 
of the three-judge court which struck down Sec. 3313.66 of the Ohio 
Revised Code. The opinion of Justice Byron White, writing for the 
majority (Justices Douglas, Brennan, Stewart and Marshall) was 
straightforward. After reviewing the facts and Ohio statutory 
authority for suspending students Justice White addressed the crucial 
threshold question: did the students have a constitutionally protected 
interest? Neither his affirmative answer nor his reasoning represented 
a startling doctrinal innovation. For the purpose of determining 
whether plaintiffs had a constitutionally protected interest the 
majority did not view the student as markedly different from a 
governmental employee, a welfare recipient, a prisoner, or a parolee. 
The constitutionally protected property interests which any of these 
groups had, the majority stated, were:

"not created by the Constitution. Rather, they are created and
their dimensions are defined" by an independent source such as
state statutes or rules entitling the citizen to certain 
benefits. [footnote reference - "_Id._ at 572-3"].

The Court accepted the argument that plaintiffs and the _Amici_ made
in their briefs; i.e., that Ohio laws guaranteeing free public 
education and compelling school attendance created an entitlement:

Here, on the basis of state law, appellees plainly had
legitimate claims of entitlement to a public education. Ohio
Rev. Code Ann. subsec. 3313.48 and 3313.64 (1972 Supp. 1973)
direct local authorities to provide a free education to all
residents between five and twenty-one years of age, and a
compulsory-attendance law requires attendance for a school
year of not less than thirty-two weeks. Ohio Rev. Code Ann
Sec. 3321.04 (1972). [footnote reference - "_Id_ at 573."]
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