With his sustained blitz of television appearances and speeches, former Vice President Dick Cheney has established himself as perhaps the leading Republican voice against President Obama.

Not a bad time, then, to be in the market for a multimillion-dollar book contract.

Mr. Cheney is actively shopping a memoir about his life in politics and service in four presidential administrations, a work that would add to what is already an unusually dense collection of post-Bush-presidency memoirs that will offer a collective rebuttal to the many harshly critical works released while the writers were in office and beyond.

Already working hard to meet publishers’ deadlines is an informal writers’ workshop of historic proportions: President George W. Bush; Laura Bush, the former first lady; former Secretary of State Condoleezza Rice; former Treasury Secretary Henry M. Paulson Jr.; former Defense Secretary Donald H. Rumsfeld; and Karl Rove, the former presidential political mastermind.