After a day of whiplash federal court rulings that eventually led to the blocking of Texas’s new boundary-testing immigration enforcement law, the U.S. Fifth Circuit Court of Appeals heard arguments Wednesday on whether Senate Bill 4 should go back into effect while the broader legal case plays out.SB 4 seeks to make illegally crossing the border a class B state misdemeanor, carrying a punishment of up to six months in jail. Repeat offenders could face a second-degree felony with a punishment of two to twenty years in prison.It’s designed to give state and local authorities new power to enforce the state’s border with Mexico, a job that has previously been left to the federal government. The law also requires state judges to order migrants returned…