Carson District Judge James Wilson on Wednesday issued a preliminary injunction barring the Alliance for America's Future from running pro-Brian Sandoval commercials until and unless the group registers as a Nevada Political Action Committee.The Alliance, a Virginia-based nonprofit, has refused to register and disclose who its contributors are, claiming that would violate its First Amendment rights to free speech. A spokesman said Tuesday there are also fears of retaliation against some of the contributors.But the Secretary of State's office filed to stop the TV ads, saying the Alliance is a PAC and required to register before engaging in political advocacy."This …