K Street heavy hitter Akin Gump has hired two veteran GOP lobbyists — including a former chief of staff to Senate Majority Leader Mitch McConnell (R-Ky.) — in a boost to the firm’s Republican lobbying roster.

Hunter Bates, McConnell’s chief of staff and chief counsel from 1997 to 2002, joins from Republic Consulting, the boutique four-person GOP lobby firm he co-founded with former Kentucky congressman Geoff Davis. Justin McCarthy, former congressional-affairs liaison to President George W. Bush, joins from the lobby shop Peck Madigan Jones.

Democrats appear poised to retake the Senate in November, according to the latest polls, but they will not have a large enough majority to move bills without some Republican support. For lobby firms, this dynamic means they’ll need lobbyists with ties to both Senate Republican and Democratic leaders to successfully advocate on legislation.

Akin Gump is the nation’s largest lobby firm by revenue, raking in nearly $40 million last year.

Bates will seek to bring his clients over to Akin, including tobacco company Altria, pharmaceuticals makers Amgen and Eli Lilly. McCarthy’s clients include Business Roundtable and the Business Software Alliance.

Akin Gump has deep roots in Democratic politics dating back to the days of co-founder Bob Strauss, the dynamic Democratic Party chairman. But like most large lobby firms, they have over the decades evolved into a bipartisan lobbying shop as the influence industry expanded. The firm’s high-profile Democrats include former California congressman Vic Fazio, former North Carolina senator Kay Hagan, and a former top aide in President Obama’s White House and a former chief of staff to Sen. Patrick J. Leahy (D-Vt.), Ed Pagano.

Hagan, who lost her reelection in 2014 and joined the firm in early 2016, is close to completing her two-year “cooling off period,” after which she is free to lobby her former Senate colleagues. A firm spokesman said no decision has been reached yet whether she will register to lobby.