WASHINGTON—More than two dozen states have passed laws opposing a movement to boycott, divest and sanction Israel over its treatment of Palestinians—but federal courts are split on whether the laws violate the First Amendment.

At least 27 states, including New York, Ohio and California, have laws to curb the Boycott, Divestment, Sanctions movement, according to the American-Israeli Cooperative Enterprise, a nonprofit focused on strengthening the U.S.-Israel relationship. This week, Florida, which is among those states, is...