GRAND RAPIDS, Mich. — Opening statements Wednesday in the trial of four men accused of plotting to kidnap Gov. Gretchen Whitmer offered contrasting narratives colliding in one of the nation’s most important cases of violent extremism. Prosecutors described violent extremism by men predisposed to kidnapping the governor while defense lawyers faulted what they characterized as an FBI team of rogue agents and snitches who orchestrated a conspiracy and entrapped the alleged plotters. Kidnapping Whitmer was one part of what plotters hoped would trigger a second Civil War, prosecutors told jurors We…