Donald Trump's election as President of the United States in November 2016 may have changed the nature of the political game in several ways, not least by its demotion of the importance of Big Money. Big Money is receding from the scene, leaving a vacuum, and Big Data is poised to fill that space. The people who worry about Big Money in politics - as well as the people who shrug and accept it - have agreed in recent decades that the key connection between such money on the one hand and electoral success on the other is advertising: especially broadcast advertising Yet the Hillary Clinton campaign spent a good deal more than Trump's campaign did on advertising. In the first two months of general election political advertising (mid-June to mid-August), her campaign spent $61 million on broadcast ads, while allied independent groups spent another $43 million in her cause. Trump's campaign didn't spend a dime on broadcast ads during that period, and its independent...