Senate GOP is attempting to either impede the Russian investigation and or smear the acting FBI Director McCabe...

Acting FBI boss McCabe referred to Justice watchdog for new investigation over potential conflicts in Russia case.

https://www.circa.com/story/2017/06/...n-russia-probe

The Chairman is also asking the Inspector General to investigate the ongoing sexual discrimination lawsuit filed by former FBI Special Agent Robyn Gritz, which named McCabe and other FBI officials, who she accused of impeding her work within the bureau.
Gritz's complaint was supported by then former Defense Intelligence Agency director Lt. Gen. Michael Flynn. Flynn, who went on to become President Trump's National Security Advisor, was subsequently fired after highly classified information regarding a conversation he had with Russian Ambassador Sergey Kislyak was leaked to the media.
Flynn's name was captured by federal law enforcement during his phone conversations with Kislyac, but those conversations are considered classified as part of the then ongoing Russia investigation.
Grassley said he was concerned that McCabe would preside over an investigation about Flynn when Flynn was a potentially hostile witnesses against McCabe and the FBI in an unrelated case.