CNN — A pointless argument battered Washington for much of this year over whether the southern US border is in crisis. But no one is now doubting the chaos and potential migrant surge that could be triggered by an imminent policy shift next week. The expiry on Wednesday of a Trump-era order that exploited public health justifications during the pandemic to turn away thousands of migrants is expected to severely strain an already stretched border, immigration and asylum system. The Department of Homeland Security unveiled Thursday an emergency six-point plan to tackle the crisis as Republicans preparing to take over...