President Joe Biden speaks to the press before boarding Marine One on the South Lawn of the White House in Washington, DC, on February 29. Andrew Caballero-Reynolds/AFP/Getty ImagesPresident Joe Biden’s visit to the US-Mexico border to hammer Republicans over the failed Senate border bill, which included tough border security measures, marks a dramatic shift for a White House that generally distanced itself from the issue. Since Biden took office, officials have grappled with record migration across the Western Hemisphere fueled by the toll of the coronavirus pandemic. Images of…