There are fundamental differences between how juries work and how grand juries work. In general, grand juries are chosen at random by the court. Someone chosen can provide reasons why they cannot serve but if the reasons are determined to not be valid, they must serve. The grand jury can be challenged if it is believed they were not legally selected. An individual's selection can be challenged only if it is believed they are not eligible to have been selected. So in an area that is predominantly democrat, the grand jury will be predominantly democrat, assuming a truly random selection.
For a federal grand jury, 12 votes are needed from a group of 16-23. With DC being about 28% self reporting as republican, 56% self reporting as democrat, and 18% self reporting as leaning neither way, 17 jurors are needed to have 12 people who aren't republicans. With a full 23 jurors, 13 of them, statistically, would be democrats. So while the whole grand jury may not be chosen by the democrats, there are other ways to help ensure enough democrats are present.
Information is provided to the grand jury by the prosecution. They present whatever they feel is needed. The defense does not participate in the grand jury process. They are not even present. The standard for the grand jury is probable cause, a pretty low bar when all of the evidence comes from one side.
Have you even been involved in the grand jury process, either serving on one or testifying in front of one? A grand jury indictment doesn't mean much. There's a reason it is said that a grand jury can indict a ham sandwich.
He's not accused of "questioning". He's accused of actively conspiring with others to overturn it. 4 people have already pled guilty in the Georgia case.
