Cuomo, Accused of Party Disloyalty, Backs Legislator Facing the Same Charge

By THOMAS KAPLAN

Gov. Andrew M. Cuomo and State Senator Jeffrey D. Klein both face primaries on Tuesday in part because they have helped Republicans keep power in the State Senate.

G. Oliver Koppell, at right, on Sunday. 

He is challenging Mr. Klein

  Credit Emon Hassan for The New York Times

The issue of party loyalty in the Senate has provided fodder for multiple primary campaigns this year. Mr. Klein agreed in June to end his coalition with the Republicans and reunite with his fellow Democrats after the November elections, but some liberals remain skeptical about his pledge and resent the formation of the coalition in the first place.