Were Obama’s Early Ads Really the Game Changer?

Many post-mortems of the 2012 presidential campaign suggest that Mitt Romney erred by allowing President Obama to “define” him early through an advertising blitz in battleground states. …

The problem, however, is that there is very little evidence that these early ads mattered much, according to research I have done along with Lynn Vavreck, a political scientist at the University of California, Los Angeles, for an upcoming book, The Gamble. [cont.]

John Sides, George Washington U., FiveThirtyEight (NYT)