During the Progressive Era of the 19th century, these limitations on majority power chafed Progressives who were in the legislative majority. They wanted to make big changes, and the Constitution’s limitations made that hard. Progressive legislation kept losing in the courts, who kept pointing out that it was inconsistent with Constitutional limits on government power, and Constitutional protection of things like private property rights.

This led to a rule of judicial restraint that was the beginning of the democratic constitution, where majority power reigned supreme. Its first major appearance was in an article by Harvard law professor James Bradley Thayer, arguing that courts should not strike down laws as unconstitutional, so long as they could imagine a reasonable person thinking them valid. Only in cases of clear mistake should judicial review lead to laws being held unconstitutional.

This thinking found its first Supreme Court application just a few years later in the 1896 case of Plessy v. Ferguson, upholding segregation under the famous “separate but equal” formulation (though this phrase was not part of the opinion). Echoing Thayer, Justice Brown wrote “We cannot say that a law which authorizes or even requires the separation of the two races in public conveyances is unreasonable.” Also at that time, as Barnett notes, writers stopped talking about courts’ duty to strike down unconstitutional laws and started talking about their power to do so. Not exercising a duty is a dereliction; not employing a power could be characterized as self-restraint.