This week, in honor of the G.O.P. Convention, In The Past Lane explores the history of the Republican Party. I speak with historian Heather Cox Richardson, author of a superb history of the Republican party that tracks how the GOP has shifted back and forth between being the party of big business and Wall St and the party of the people and the common good. And she'll bring her analysis all the way to the present to help put Donald Trump in historical perspective. American History