Oh, how cruel the game of politics can be — especially if you don’t have a ground game. On Sunday night, Donald Trump tweeted, “Just to show you how unfair Republican primary politics can be, I won the State of Louisiana and get less delegates than Cruz — lawsuit coming.” It’s true: On March 5, Mr. Trump took 41.4 percent of the Louisiana vote compared with Ted Cruz’s 37.8 percent and Marco Rubio’s 11.2 percent. Mr. Trump was awarded 18 delegates, so was Mr. Cruz, and Mr. Rubio got 5 delegates. So what happened between March 5 and Sunday? Mr....