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Page Number: 10.0

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UNITED STATES v. VAELLO MADERO 

THOMAS, J., concurring 

legislation by Congress as amounts to a denial of due pro-
cess,” i.e., legislation that would fail rational-basis review. 
Hirabayashi v. United States, 320 U. S. 81, 100, 102 (1943). 
In Bolling v. Sharpe, 347 U. S. 497 (1954), the Court be-
gan in earnest to fold an “equal protection” guarantee into 
the  concept  of  “due  process.”    Decided  the  same  day  as 
Brown v. Board of Education, 347 U. S. 483 (1954), Bolling
confronted  the  constitutionality  of  government-imposed
segregation in the District of Columbia’s public schools.  Be-
cause  any  such  segregation  was  attributable  to  Congress, 
see U. S. Const., Art. I, §8, cl. 17, rather than state action, 
the Equal Protection Clause did not apply.  Bolling instead 
read  an  equal  protection  principle  into  the  Fifth  Amend-
ment’s requirement that “[n]o person shall . . . be deprived
of life, liberty, or property, without due process of law.”  See 
347 U. S., at 498–500. 

Bolling’s locating of an equal protection guarantee in the 
Fifth Amendment’s Due Process Clause raises substantial 
questions.  First, Bolling’s interpretation seemingly relies 
upon the Lochner-era theory that “unreasonable discrimi-
nation” is “a denial of due process of law.”  347 U. S., at 499 
(citing Buchanan v.  Warley, 245 U. S. 60 (1917)); see also 
347  U. S.,  at  500  (“Segregation  in  public  education  is  not 
reasonably  related  to  any  proper  governmental  objective” 
and  therefore  “constitutes  an  arbitrary  deprivation  of  . . . 
liberty”); see Lochner v. New York, 198 U. S. 45 (1905).  By
invoking “due process” to hold an allegedly “unreasonable”
or  “arbitrary”  legislative  classification  unconstitutional, 
Bolling made clear that it was applying this Court’s “sub-
stantive  due  process”  doctrine.    See  N. Chapman  & 
M. McConnell,  Due  Process  as  Separation  of  Powers,  121
Yale L. J. 1672, 1800 (2012) (“[W]hen the Court purports to 
evaluate whether a state’s interest is ‘legitimate’ or a ‘jus-
tif[ied]’ interference with a judge-made liberty, the result is 
no different in principle than in other modern substantive 
due process cases”).