Political parties and democratic politics go hand in hand. Since parties matter, it matters too when elected politicians change party affiliation. This book shows why, when, and to what effect politicians switch parties in pursuit of their goals, as constrained by institutions and in response to their environments.

WILLIAM P. HELLER is Associate Professor of Political Science, Binghamton University, USA.
CAROL MERSHON is Associate Professor, Department of Politics, University of Virginia, USA.