By Joshua FechterThe Texas TribuneThe U.S. Department of Justice has threatened to sue to stop a new Texas law that allows state police to arrest people suspected of illegally crossing the border — unless Gov. Greg Abbott backs off of enforcing the law.The new law, known as Senate Bill 4, is “unconstitutional and will disrupt the federal government’s operations” vis-à-vis immigration and border enforcement, an agency official told Gov. Greg Abbott in a letter first reported Thursday by the Houston Chronicle and later posted on social media by a CBS News reporter.If Texas does not formally refrain from enforcing the ...