There's a compromise available
If there is sensitive information about how the RNC conducts its business, only allow the two republican members of the committee, and their staff, to view that information and decide whether it is relevant to the investigation.
There is precedent for this, there have been a few members of the Trump white house or Trump campaign who weren't comfortable being questioned by democratic members of the committee, so the committee agreed to let the two republican members conduct those interviews alone.
Biting the hand that feeds IT
