I was under the impression that if a law passes constitutional muster, the motivations behind the law are irrelevant to the Court. So why fixate on this notion that the law was a solution in search of a problem?

Well learn to read and you might learn another thing or two...

under the balancing approach of earlier cases (which the opinion says comes from cases such as Anderson and Burdick), a state needs to come forward with merely plausible non-discriminatory interests to justify an election law.

In other words, the motivation is explicitly PART of whether the law passes constitutional muster.

No need to be snotty about it.

:0(

Nonsense, this is activist baloney. Obviously, activist judges are going to give unconstitutional laws a pass because "they meant well". Motivation is irrelevant, otherwise no law would be unconstitutional, because every law is made with "good intentions". Constitutionality is determined by whether the law observes the restrictions on government found in the Constitution.