Possible legal challenges could impact race between Michelle Nunn (D) and David Perdue (R).
"Apparently, the Nunn team feels they can repeatedly disregard" Bush's "wishes."
Democrat Michelle Nunn leads Republican David Perdue 48 percent to 45 percent.
Michelle Nunn (D) raised $3.45 million, besting both of her GOP Senate opponents combined.
Perdue leads Handel by 22 percent to 20 percent in the bitter Georgia GOP Senate primary.
Looming runoffs in Louisiana and Georgia could extend Election Day until January.
The former New York City mayor gave $350,000 to a group backing Michelle Nunn's (D) Senate bid.
After a rough week for David Perdue (R), Senate Democrats are suddenly upbeat.
Kingston and Perdue used the lone opportunity ahead of next Tuesday to wage personal attacks.
The former VP nominee calls the Ga. Senate hopeful a "conservative who has walked the walk."