The Senate contest has reverberated around the Peach State, creating three open-seat House races with GOP runoffs that will also be decided Tuesday.
In the statewide race, many Republicans said Rep. Jack Kingston, R-Ga., has a small edge over former Dollar General and Reebok CEO David Perdue. Both of whom have spent millions on the anticipated low-turnout contest, and polls close at 7 p.m.
But turnout in a mid-summer runoff is unpredictable. And a Republican runoff in Kingston's 1st District could also help boost the congressman's chances because turnout may be higher in his geographic base.
The Senate race is rated Favored Republican by the Rothenberg Political Report/Roll Call.
All three House races are rated Safe Republican contests by the Rothenberg Political Report/Roll Call.
1st District State Sen. Buddy Carter and surgeon Bob Johnson are vying for the Republican nomination in Kingston's Savannah-based district. In the May primary, Carter came in first in the six-candidate field with 36 percent, and Johnson trailed with 23 percent.
GOP operatives said Carter has the edge in the runoff too. The Club for Growth spent more than $380,000 against Carter in the runoff, which makes his path to victory more difficult.
The GOP nominee is expected to be the next member of Congress from this district, which voted for GOP presidential nominee Mitt Romney with 56 percent in 2012.
10th District Baptist pastor Jody Hice and trucking company owner Mike Collins are in the runoff for this seat, which is open due to GOP Rep. Paul Broun's failed Senate bid . The district includes the Augusta and Atlanta exurbs.
Hice bested Collins by 270 votes in the seven-way primary , and both advanced to the runoff with 33 percent.
Collins, the son of former Georgia Rep. Mac Collins, boasts endorsements from conservatives such as former Sen. Rick Santorum, R-Pa., and former Speaker Newt Gingrich, a Georgia native.
Hice, a pastor and radio show host, is backed by Broun .
Like the 1st District, the 10th District's GOP victor is all but certain to win in November. Romney carried the district by a 26-point margin in 2012.
11th District Rep. Phil Gingrey's unsuccessful Senate bid left his Marietta-based district open. On Tuesday, former Georgia Rep. Bob Barr and former state Sen. Barry Loudermilk will face off for the Republican nomination to succeed him in Congress.
Loudermilk is the clear favorite.
Despite Barr's familiarity with voters from a long history in Georgia electoral politics, Loudermilk came in first in the May 20 primary with 37 percent. Barr trailed with 26 percent.
An internal poll from Loudermilk's campaign showed him up by double digits. That poll, conducted July 7 and 8, had Loudermilk up 49 percent to Barr's 28 percent.
With no Democrat on the ballot in this district in the fall, whomever earns the 11th District Republican nomination is almost certainly the next member of Congress from this district.
Kyle Trygstad contributed to this report Related Stories: Super PAC Targets Democrat in Georgia Deepening of Savannah Port Is an Issue in Jack Kingston-David Perdue Race Kingston Counts on Hill Connections in Senate Runoff Paul Broun Endorses Candidate in Georgia Roll Call Election Map: Race Ratings for Every Seat Get breaking news alerts and more from Roll Call in your inbox or on your iPhone.