"The border is closed": With those words, a top Biden administration official on Sunday pushed back against fast-mounting criticism that it has bungled immigration policy, spurring an influx of migrants in the biggest crisis to emerge under the new president. Homeland Security Secretary Alejandro Mayorkas said the administration's message to would-be border-crossers was simple: "Now is not the time to come. Do not come. The journey is dangerous. "We are building safe, orderly and humane ways to address the needs of vulnerable children," he said on ABC's "This Week." "Do not come." But with an estimated 15,000 migrant children or teenagers already in federal custody - roughly a third of them in facilities meant for adults - and with the nation on pace to see two million undocumented migrants arrive this year, the magnitude of the problem has become impossible to ignore. Bipartisan criticism Many Republicans, but also a growing number of Democrats, have criticised the administration's border policies. Mayorkas, appearing on three television networks, insisted that the administration was doing everything it could to address the influx, but said the task was complicated by policies...