As someone (I forget who) pointed out today, campaign contributions of that amount are solicited. So yes, they knew exactly whose money they were taking:
WASHINGTON — Two U.S. senators and one congressman from Nebraska and Iowa received political donations from the leader of a white supremacist group cited by Charleston church slaying suspect Dylann Roof.
The Guardian newspaper first reported that Earl Holt of Texas has given more than $60,000 to Republican campaigns in recent years. Holt is the leader of the Council of Conservative Citizens.
Those donations included $1,000 to Sen. Joni Ernst, R-Iowa, and $2,000 to Sen. Ben Sasse, R-Neb., in the last cycle. Both won in open-seat contests in their respective states.
Tyler Grassmeyer, Sasse’s deputy chief of staff, provided a written statement to The World-Herald.