Perdue and Loeffler are both in a runoff for Senate seats
The GOP candidates for the two open Senate seats in Georgia are asking for the Secretary of State of Georgia to resign. According to the joint statement , the Republican Sec. of State "failed to deliver honest and transparent elections. He has failed the people Georgia, and should step down immediately".
The runoff election will be on January 5th. It is likely the GOP will hold a 2 seat majority going into those elections. If that is the case, the runoffs could lead to a split Senate. The VP would cast the deciding vote in the event of tied votes.
Loeffler and Perdue will run against Democrats Raphael Warnock and Jon Ossoff. In Georgia if a candidate does not reach a 50% majority in a election race, there is a runoff between the two highest vote getters.