Karyn Brockman will serve as finance director, while Ty Matsdorf will serve as campaigns and communications director.
Brockman most recently worked as finance director for Sen. Chris MurphyChris MurphyWeek ahead in health: All eyes turn to Dem convention Overnight Healthcare: Mysterious new Zika case | Mental health bill in doubt | Teletraining to fight opioids Hopes dim for mental health deal MORE (D-Conn.), helping him raise more than $10.5 million to face Linda McMahon, one of the best-funded Republican Senate contenders in the nation.
Matsdorf most recently worked as war room director and senior adviser for American Bridge 21st Century, the Democratic super-PAC affiliated with opposition research group American Bridge.
Majority PAC spent nearly $40 million last cycle and found success in a large majority of the races in which it invested.
Then, Democrats faced a tough fight to retain the majority in the Senate, with a number of early retirements and incumbents in competitive presidential states complicating their efforts, but the party eventually managed to pick up seats.
Democrats face a similarly challenging map this cycle, as they're defending nearly twice as many seats as Republicans, seven of which President Obama lost.