Updated

Sun., December 14 at 3 p.m. ET
Hosted by Chris Wallace

The most powerful office in the world. The world's most powerful medium. Together, they've changed the course of history.

In the fourth chapter of our 5-part series, we'll examine how two presidential candidates used television in a notorious battle of commercials, how television became a key player in a real war and how a little-known Southern governor changed the face of American politics.

Michael Dukakis' appearance in a tank showed what can happen if you underestimate the power of this television. We'll take a look at what lessons were learned and who learned them.

In 1988, George Bush won decisively. But the Cold War still bubbled and television was about to change how presidents do their job.

Then, flash forward to 1992, as among the Democrats who wanted to challenge President Bush, a young Southern governor was assembling a team that understood the new political landscape better than most.