Most of this is directly from their own website. In many cases they're reluctant to state that the people involved are republicans.
www.mercuryllc.com/capabilities/government-relations/
Kevin Allen - Political Appointee in the Bush Administrations Commerce Department (ITA) and the U.S. Department of State (USIA) for the 1993 Korea International Trade Exposition, Staff for the Chairman of the Republican National Committee on the 1984 and 1988 Republican National Conventions
Al Barlas - Legislative Director for then-Assemblyman Declan OScanlon before serving as Chief of Staff to State Senator Kevin OToole (both republicans). Worked with the Governors (Christie) office on behalf of the Senator and Assemblyman. Chairman of the Essex County Republican Committee.
Kevin Marino Cabrera - Prior to joining Mercury, Kevin worked as Florida State Director for Donald J. Trump for President and the Republican National Committee, managed Trump Victorys Florida budget.
Caroline Delleney - Prior to joining Mercury, Caroline served as the Deputy Chief of Staff and Communications Director to the (republican) South Carolina Speaker of the House. Caroline previously spent six and half years in Washington, DC, working for a (republican) Congressman from South Carolina in various capacities. As his Executive Assistant, she directed and briefed the Congressman on his day-to-day activities and acted as a liaison between other Congressional offices. For most of her time in Washington, Caroline served as the Congressmans Communications Director. (note, they neglect to say who that is, it's Joe ("YOU LIE!" ) Wilson!)
Jack Deschauer - General Consultant to (republican) Congressman Ryan Costellos successful 2014 election campaign. Managed Pennsylvania (republican) Senate Majority Leader Dominic Pileggis web advertising for his campaign. Oversaw efforts in several congressional districts in New York and New Jersey for the American Action Network, resulting in the re-election of four (republican) incumbents in NJ3, NY11, NY19, NY22, and a pick-up in NY27. Regional Political Director for Mayor Rudy Giulianis presidential campaign, directing efforts in 14 states. Political Director for the Republican Party of Pennsylvania in 2004.