A federal judge in Kansas on Tuesday temporarily blocked that state's law requiring contractors to certify they do not support boycotts of Israel.
District Judge Daniel Crabtree agreed to issue the preliminary injunction until a final ruling is issued in the case.
"Pending further order from this court, the court enjoins defendant from requiring any independent contractor to sign a certification that they are not participating in a boycott of Israel as a condition of contracting with the State of Kansas," Crabtree wrote in a 28-page decision.
The American Civil Liberties Union (ACLU) is representing Esther Koontz, a member of the Mennonite Church USA, a pro-peace Anabaptist Christian denomination. Koontz is a mathematics teacher who declined to issue the state-required anti-Boycott Divestment and Sanctions (BDS) certification, and lost out on state contracts as a result.
ACLU attorney Brian Hauss, who argued the issue in court, said in a statement the court "has rightly recognized the serious First Amendment harms being inflicted by this misguided law, which imposes an unconstitutional ideological litmus test".
The First Amendment of the Constitution guarantees freedom of speech, among other rights, and is one of the most staunchly defended constitutional clauses. The Supreme Court ruled in 1982 that the First Amendment protects the right to boycott.
"This ruling should serve as a warning to government officials around the country that the First Amendment prohibits the government from suppressing participation in political boycotts," Hauss said.
Crabtree's ruling is the first that has upended a growing set of state laws that have prohibited BDS supporters from exercising the ban.
Following Hurricane Harvey that inundated wide swathes of Texas, including its largest city, with unprecedented torrents, those seeking to receive state recovery assistance were forced to certify they would not boycott Israel.
Texas Gov. Greg Abbott signed the state's anti-BDS bill in May, saying "Anti-Israel policies are anti-Texas", setting the stage for the controversy to unfold.
A bill in Congress to criminalize BDS support with possible punishments including 20 years in jail and up to $1 million in penalties has sputtered amid widespread backlash. The Senate sponsors of the bill are seeking to amend it.