The standard narrative of the Lady Bird and Lyndon Johnson relationship assumes that he married her for her money and she followed him on his ascent to the presidency. According to a new book about the couple, though, the first lady was an equal political partner often called upon to broker backroom deals for the president. This hour, we’ll talk with Betty Boyd Caroli about her new book, “Lady Bird and Lyndon: The Hidden Story of a Marriage That Made a President” (Simon & Schuster). Boyd speaks tonight at Highland Park United Methodist Church’s Authors Live! event.