Senator Feinstein was one of the loudest voices for the charge Trump is a Russian asset. As her hoax unfolded, it emerged that Feinstein employed a Communist Chinese spy as her driver for almost 20 years: FBI deported him quietly, Dems deny he was "real
This spy also served as in Feinstein’s San Francisco office and even attended Chinese Consulate functions for the senator. The spy remained in place for three election cycles but Sen. Feinstein never faced high-volume charges of channeling foreign influence in American elections.
https://californiaglobe.com/section-2/sen-dianne-feinstein-cries-racism-over-coronavirus/
Feinstein is on the Senate Intelligence Committee during these times, having access to (secrets*)
Famously, Bush enraged her by denying her access to military documents and higher intelligence during the Iraq war. She tried to arrange an ousting of Bush based on the accusation that Congress, not the President, should have clearance to military intelligence.