Anyone who doubts that Hillary Clinton is already in fine fighting trim for a presidential run should consider her speech this week to the American Bar Association in San Francisco. She assailed an alleged “assault on voting rights.” She took aim at the Supreme Court’s recent decision striking down a portion of the Voting Rights Act and excoriated states that have recently tightened their voting laws. She declared that “anyone who says that racial discrimination is no longer a problem in American elections must not be paying attention.” Madam Secretary hasn’t missed a beat. She knows that the calling card...