The Politics of Presidential Impeachment takes a distinctive and fresh look at the impeachment provision of the US Constitution. Instead of studying it from a legal-constitutional perspective, the authors use a social science approach incorporating extensive case studies and quantitative analysis. Focusing on four presidents who faced impeachment processes—Andrew Johnson, Richard Nixon, Ronald Reagan, and Bill Clinton—they examine the conditions under which presidential impeachment is likely to occur and argue that partisanship and the evolving relationship between Congress and the president determine its effectiveness as an institutional constraint. They find that, in our contemporary political context, the propensity of Congress to utilize the impeachment tool is more likely, but given the state of heightened partisanship, impeachment is less likely to result in removal of a president. The authors conclude that impeachment is no longer a credible threat and thus no longer an effective tool in the arsenal of checks and balances. The book also offers a postscript that discusses the impeachment of President Donald J. Trump.