In Brennan et al. v. Armstrong et al., the Supreme Court of the United States dealt with a dispute over Connecticut's system for apportioning seats in its General Assembly, which was challenged as violating the Equal Protection Clause of the Fourteenth Amendment due to population disparities among districts. The District Court had ruled that this system did indeed violate equal protection rights and ordered a new plan to be implemented by state officials, but they failed to do so within an allotted time frame. As such, it fell upon federal courts to devise their own reapportionment scheme. The Supreme Court held that while federal courts have authority under certain circumstances to order into effect a state legislative reapportionment plan, they should exercise this power sparingly and only when necessary after giving appropriate consideration and opportunity for action by state authorities themselves first. In this case, since there was no finding that Connecticut's delay in implementing a new plan was caused by any dilatory tactics or bad faith on part of its officials nor were there imminent elections threatening immediate harm from existing malapportioned legislature; hence ordering into effect court-devised plans prematurely wasn't warranted.

In the dissenting opinion for Brennan et al. v. Armstrong et al., Justice William J. Brennan Jr., joined by Justices Thurgood Marshall and Byron White, argued that the majority's decision to uphold Connecticut's Sunday closing laws violated the Establishment Clause of the First Amendment because it advanced a particular religious practice without a secular legislative purpose. The dissenters contended that while some may argue these laws serve a secular purpose in providing a uniform day of rest, this argument is undermined by numerous exceptions allowed under these laws which do not align with this supposed goal. They further pointed out that many who observe their Sabbath on days other than Sunday are disadvantaged by such legislation, thus favoring one religion over another - an action prohibited under the Constitution’s Establishment Clause.