v.

remove from political office

"The Republicans are trying to unseat the liberal Democrat"

dislodge from one's seat, as from a horse

Serta unseats Simmons
Nguyen unseats VanRavenswaay in runoff
HP unseats TI at top of MEMS rankings for 2007
Indiana Unseats Minnesota In Charter-Law Rankings
Waxman Unseats Dingell from Energy & Commerce Committee
Indiana Unseats Minnesota in Charter School Law Ranking
Burns unseats Pittard to pip him to the win in the weekend's finale
Study: Imeem Unseats Yahoo as Top U.S. Music-Streaming Site (Updated)
UnitedHealthcare Unseats WellPoint as the Leading Health Insurer according to Mark Farrah Associates
A Law and Order Campaign: Lawyer, 29, Unseats Long-Term DA in Luzerne County, Pa. -- Magazine -- ABA Journal