The super PAC dedicated to helping Democrats win back the Senate is announcing several new senior staffers for the 2018 cycle, according to an announcement shared first with Roll Call.

J.B. Poersch, president and co-founder of the Senate Majority PAC, said in a statement that the group had assembled a “first-rate team” in the face of a “challenging Senate map.” Senate Democrats are defending 25 seats next year compared to the Republicans’ eight.

“This team gives us the best chance to move towards a Senate majority by defending our incumbents and flipping seats,” Poersch said.

Among Senate Majority PAC’s news hires is its first digital director since the group was founded in 2011. Pamela Stamoulis, who recently worked at a New York public strategy firm, will lead the digital campaign effort aimed at mobilizing voters.

The new hires also include a few veterans of Hillary Clinton’s presidential campaign.

Angelique Cannon Harris will serve as the group’s national finance director. She worked as Clinton’s deputy national finance director for the mid-Atlantic region and had previously been the finance director at the DSCC.

Alexandra Shapiro will serve as Senate Majority PAC’s new deputy national finance director. She previously worked on the mid-Atlantic finance team for the Hillary Victory Fund, and has worked at the Democratic National Committee as the mid-Atlantic finance and PAC director.

Poersch is a former executive director of the Democratic Senatorial Campaign Committee, serving from 2005 to 2010. He oversaw the committee while New York Sen. Charles E. Schumer was chairman and Democrats won back the Senate in 2006. Schumer is now the Senate minority leader.

Some alumni from 2016 Senate campaigns have joined the Senate Majority PAC. Diana Astiz joins the group as research director. She was previously research director for Pennsylvania Democrat Katie McGinty’s unsuccessful Senate campaign against GOP Sen. Patrick J. Toomey.

Chris Hayden, formerly with the Center for American Progress Action Fund, will serve as the new communications director. He also worked as the communications director last cycle for Missouri Democrat Jason Kander, who lost to Republican Sen. Roy Blunt.

Former Schumer staffer Alex Katz is joining the group as a senior adviser in New York. Katz served on Schumer’s staff for four years both in New York and Washington.

The Senate Majority PAC operates independently of Senate campaigns. As as a super PAC, the group can spend millions of dollars supporting Democratic senators and candidates. In 2016, it spent more than $91 million, according to Open Secrets.org.