logroller (?.)

• Machiavellian
• behind-the-scenes operator
• eminence grise
• finagler
• five-percenter
• fixer
• four-percenter
• gamesman
• gray eminence
• influence peddler
• kingmaker
• machinator
• operator
• pork-barrel politician
• power broker
• strategist
• wheeler-dealer
• wire-puller