The state of Texas filed an audacious lawsuit in the Supreme Court on Tuesday against four other states, asking the justices to extend the Dec. 14 deadline for certification of presidential electors. The suit, filed by the state’s attorney general, Ken Paxton, said Georgia, Michigan, Pennsylvania and Wisconsin had engaged in election irregularities that require investigation, and it asked the court to “enjoin the use of unlawful election results without review and ratification by the defendant states’ legislatures.” Legal experts called the suit outlandish, and it comes at a time when Mr. Paxton is battling a scandal in his own...