On December 1, former U.S. Supreme Court Justice Sandra Day O’Connor died. She had been one of the last justices to write anything favorable about minor parties. In 2005, in Clingman v Beaver, she wrote, “Although the State has a role to play in regulating elections, it is not a wholly independent or neutral arbiter. Rather, the State is itself controlled by the political party or parties in power, which presumably have an incentive to shape the rules of the electoral game to their own benefit…As such restrictions become more severe, and particularly where they have discriminatory effects, there is increasing cause for concern that those in power may be using electoral rules to erect barriers to electoral competition. In such cases, applying heightened scrutiny helps to ensure that such limitations are truly justified and that the State’s asserted interests are not merely a pretext for exclusionary or anticompetitive restrictions.”
Clingman v Beaver was not a ballot access case. It was a Libertarian Party case on the ability of parties to control their own nomination process. But O’Connor as well as Justice John Paul Stevens were moved to write about ballot access restrictions. Justice Stephen Breyer co-signed the O’Connor language quoted above.
No full decision of the U.S. Supreme Court since then has talked about minor party or independent candidate ballot access.