Republicans on Capitol Hill listened dutifully as President Donald Trump blamed Democrats for the immigration crisis on the southern border that he created, tweeted demands that they agree to an immigration overhaul he wants and recalled the Homeland Security chief from New Orleans to deliver a feisty defense of his policies. Then they went their own way. Despite the prodding from the White House, many Republicans on Monday declined to follow Trump’s cues on a policy of separating parents and children who are apprehended crossing the border.