My guess is they knew he would put their lies at risk with his own improprieties.
>Blumenthal (D-CT) Lied about service in Vietnam.
>Booker (D-NJ) Lied about texting a stripper and later kav docs (Spartacus).
>Cortez Masto (D-NV) Colluded with the DA and lied to a NV judge about them not having a "Dishonest Cop Liar's List" (probably to use for cover ups and dirty deeds)
>Gillibrand (D-NY) Lied about ties to NXIVM.
>Harris (D-CA) Lied about schools not being integrated when she was a kid (& Kav)
>Warren (D-MA) Lied about Indian heritage.