If President Biden moves ahead with a plan to block people who illegally cross into the United States from claiming asylum‚ it is likely to face a swift legal challenge‚ much the way an effort by his predecessor in 2018 was blocked by the courts. Politically‚ such a setback may not even matter. For Mr. Biden‚ simply issuing an executive action just before his State of the Union address on March 7 could bolster his re-election campaign by demonstrating that he is unilaterally trying to...