Expert on the American presidency and presidential powers, legislative redistricting, campaign finance reform, election law and administration and defense policy
- Presidential powers, including the constitutional powers of the office, executive orders, war powers, and history
- Current campaign finance system, history of reform, effects of campaign finance rules on electoral competitiveness.
- Election administration and legislative redistricting
- Defense policy, including procurement and acquisition; the base realignment and closure (BRAC) process
- Australian politics and elections
- Inaugural Fulbright-ANU Distinguished Chair of Political Science, Australian National University (Canberra, ACT), 2006
- 2002 Neustadt Award for best book on the presidency, "With the Stroke of a Pen: Executive Orders and Presidential Power"
- 2006 Alliant Underkofler Excellence in Teaching Award, University of Wisconsin System