Presidential campaigns narrow the battleground to an ever-smaller group of potentially pivotal states—where they spend most of their time and money in the race to 270 electoral votes. How do presidential campaigns envision and select their paths to victory? And how much do these decisions matter? Daron Shaw takes us inside the presidential campaigns from 1952 to 2020, with data and analysis from the campaigns themselves. He finds that calcified partisanship and campaign finance liberalization have moved us into a micro-targeted era, with a smaller group of mutually agreed battleground states. But resource allocation decisions can still make enough of a difference to tip the balance in several recent elections--and maybe 2024 as well.