President Joe Biden is expected to sign an executive order on Tuesday aimed at tightening measures at the US-Mexico border. The order, which has been described as the most restrictive border policy by any modern Democrat, will limit asylum requests and deny entrance to migrants once a daily threshold of 2,500 crossings is exceeded. The border will reopen for asylum seekers when the number of daily crossings falls to 1,500. This move comes as the Biden administration seeks to address an historic surge in migrants and counter GOP attacks on border security. The executive order is anticipated to face immediate legal challenges. The policy echoes a 2018 effort by President Donald Trump and has drawn comparisons to statements by former Obama-Biden DHS Secretary Jeh Johnson, who noted that 4,000 daily crossings would overwhelm the system.