The runoff election tomorrow to determine who will be the GOP nominee for the senate in November has become a pretty nasty affair, with both candidates hurling charges at one another in an air war that is depleting the campaign war chests of both men.

Rep. Jack Kingston and David Perdue have been locked in a tight race for weeks and, with a lack of reliable polling, most observers are rating the race a toss up.

The Hill:

“They’ve been beating the crap out of each other,” said Georgia-based Republican strategist Chip Lake, who is neutral in the contest.

While they duke it out, Democratic nominee Michelle Nunn is raising huge sums of money. That has some Republicans nervous about a seat that’s a likely must-win if the GOP hopes to retake the Senate majority this fall.

Georgia observers say Perdue has scratched and clawed his way back into the race, after Kingston jumped out to an early lead in the primary runoff, beating up the “career politician” in ads focusing on his more than two decades in Congress and ties with the “pro-amnesty” Chamber of Commerce.

Kingston has been fighting back, criticizing Perdue on the details of his business career and policy positions. His latest ad depicts Perdue as a mannequin, claiming he’s “out of touch with our conservative values.”

Georgia Republicans are confident that whoever wins the primary will be favored this fall, and they say the Perdue-Kingston match-up is the best they could have hoped for out of a crowded field filled with more flawed candidates. But many admit the highly charged runoff campaign could be damaging.

The few recent public polls show a tightening race, with Kingston holding a lead in the single digits. Both GOP campaigns say they expect a photo finish.

There are also few reliable public polls of the general election, but most have found Nunn ahead of or within striking distance of both of her Republican foes.

“In the closing days here as David Perdue has gone up on TV and the hits have gotten pretty hard between the two of them, this race has definitely tightened up. This is going to be a close race one way or the other,” said Joel McElhannon, another neutral Georgia Republican strategist.

Nunn has brought in $3.5 million over the last three months, more than Kingston and Perdue combined during the same period, and has $2.3 million in the bank as of the end of June, to Kingston’s $1.2 million and Perdue’s $800,000. Perdue has the ability to self-fund and Kingston is close to the business community, but it’s clear she’ll have the early cash advantage.

“When she turns in fundraising numbers like she did, obviously that’s concerning and frustrating,” one Georgia Republican said. 

Either candidate is fully capable of winning in November, so the issue of electability is off the table. And unlike Mississippi, there doesn't appear to be the Tea Party/Establishment divide that threatens the GOP's hold on the seat. Rather, this is an "insider vs. outsider" race with 20 year congressman Kingston touting his experience vs. political newcomer Perdue who is a former CEO of Dollar General. The Chamber of Commerce has poured $2.3 million into Kingston's campaign while Perdue has been able to self-fund.

Turnout is expected to be very low - below 20% by most estimates. That will probably favor Kingston who is better known and is believed to have a better GOTV operation. But in a season of surprises, it would not be beyond imagining that Perdue squeaks through and wins it.