Crypto interest group, Protect Progress PAC, has spent $7.8 million to support Democratic candidates in US Senate races.They spent $4.1 million on media buy for Ruben Gallego in Arizona and $3.7 million for Elissa Slotkin in Michigan.Protect Progress is affiliated with crypto-backed Super PACs Fairshake and Defend American Jobs.The three PACs have collectively invested millions to support and oppose congressional candidates.