US President Joe Biden tightened the rules for migrants entering the US illegally from Mexico in the middle of the election campaign. The measures, which just entered force, allow the authorities to deport people who have entered the country irregularly, in some cases without processing their asylum applications. “I’ve come here today to do what Republicans in Congress, refuse to do, take the necessary steps to secure our border,” Biden said in Washington on Tuesday. The UN refugee agency UNHCR criticized the regulation as an undermining of the basic right to asylum. US civil rights activists …