fight one's corner

Verb

 * 1)  To vigorously promote or defend one's interests, views, etc.
 * 2) * 1896, The Parliamentary Debates of the United Kingdom of Great Britain and Ireland, vol. XLIII, p. 866 (Google preview):
 * The right hon. Gentleman the Member for Trinity College, who had fought his corner well for the landlords, must know the heavy disabilities under which the tenants referred to suffered through no fault of their own.