The US Supreme Court ruled [opinion, PDF] 7-2 Thursday that a Minnesota political apparel ban within polling places violates the Free Speech Clause of the First Amendment.

Minnesota Voters Alliance v. Mansky [docket] challenged a Minnesota law [text] that banned political badges, buttons or other political insignia from being worn at or about polling places on primary or Election Day. In November 2010 the alliance’s executive director Andrew Cilek was prevented from voting because he was wearing a Tea Party shirt, as well as a button promoting efforts to require voters to show photo ID. After the election, the organization filed suit. The lower courts rejected the group’s claim that this ban was a violation of voters’ First Amendment rights, and the Supreme Court reversed.

The petitioner, Minnesota Voters Alliance (MVA), argued [JURIST report] that the statute is overbroad in its language because it bans more speech than necessary to protect the government’s legitimate interests. MVA suggested the first sentence of the statute, which bans electoral speech, is enough to accomplish the government’s goal. The court agreed.

Chief Justice Roberts wrote for the majority:

Minnesota’s ban … plainly restricts a form of expression within the protection of the First Amendment. …

Cases like this present us with a particularly difficult reconciliation: the accommodation of the right to engage in political discourse with the right to vote. … Minnesota, like other States, has sought to strike the balance in a way that affords the voter the opportunity to exercise his civic duty in a setting removed from the clamor and din of electioneering. While that choice is generally worthy of our respect, Minnesota has not supported its good intentions with a law capable of reasoned application.

The majority opinion’s Appendix also lists 34 other states that have similar state laws prohibiting accessories or apparel in the polling place.

Justice Sonia Sotomayor dissented, which Justice Stephen Breyer joined.