The initial issue presented by this case is the appropriate standard of judicial review to be applied when social and economic legislation enacted by Congress is challenged as being violative of the Fifth Amendment to the United States Constitution. There is no claim here that Congress has taken property in violation of the Fifth Amendment, since railroad benefits, like social security benefits, are not contractual and may be altered or even eliminated at any time. Hisquierdo v. Hisquierdo, 439 U.S. 572, 575 (1979); Flemming v. Nestor, 363 U.S. 603, 608-611 (1960). And because the distinctions drawn in § 231b (h) do not burden fundamental constitutional rights or create "suspect" classifications, such as race or national origin, we may put cases involving judicial review of such claims to one side. San Antonio Independent School District v. Rodriguez, 411 U.S. 1 (1973); Vance v. Bradley, 440 U.S. 93 (1979)." UNITED STATES RAILROAD RETIREMENT BOARD v. FRITZ, 101 S. Ct. 453, 449 U.S. 166 (U.S. 12/09/1980) . .