Will last minute strength be enough for Dems?

A new CNN poll puts Michelle Nunn ahead of David Perdue in the Georgia Senate race.

Story highlights

  • Candidates in Louisiana and Georgia must win 50% to win a runoff
  • Democrats in those states are ahead in some polls but haven't cleared 50%
Democrats in key Senate races are showing some strength in the final stretch of election season -- but it may not be enough to keep the chamber.
A new CNN/ORC poll released Friday shows Democrat Michelle Nunn leading Republican David Perdue 47% to 44% among likely voters. A WAFB poll out this week in Louisiana found incumbent Democrat Mary Landrieu four points ahead of Republican Bill Cassidy. And a recent Courier-Journal/Survey USA poll in Kentucky found Democrat Alison Lundergan Grimes trailing Senate Republican leader Mitch McConnell by just one point.
It's enough to make Democrats feel cautiously optimistic about their ability to hold onto the Senate. But there's a problem: in two of the races -- Georgia and Louisiana -- Democrats will need to win at least 50% of the vote to avoid a runoff. And neither candidate is clearing that threshold in polls.
The stakes are huge. Democrats could upend Republican hopes of picking up the net gain of six seats needed to claim the Senate if they find a way to succeed in these races without a runoff.
The good news-bad news scenario is reflected in today's Georgia poll.
"It is a surprising show of strength for a Democrat in a state in which no Democrat has won a statewide election in over a decade," said CNN Polling Director Keating Holland.
Democratic and Republican consultants credit Nunn, daughter of former senator Sam Nunn, with running a strong campaign.
She gained momentum in recent weeks by slamming one of former CEO Perdue's supposed strengths: his business record, and accused him of shipping US jobs overseas.
The CNN poll also shows Nunn beating Perdue 51% to 47% in a run-off election that will take place on Jan. 6 if neither candidate wins in the first round. The data, however, is based on those likely to vote in November and the electorate in run-off elections typically differs from first round votes.
As Nunn inches closer to the 50% threshold, her fate could lie with libertarian candidate Amanda Swafford, who is polling at 5% of likely voters. No one knows whether Swafford's supporters will gravitate to Perdue or simply stay home -- and their decision could have big implications for who wins the race.
An idiosyncratic election system is also a problem for Democrats in Louisiana, where Sen. Mary Landrieu led the last five polls ahead of the state's open primary, which will send two candidates to a run-off if no one wins 50% of the vote.
An outright win is eluding Landrieu. Though she's ahead of Cassidy, recent polls show her garnering only support in the high 30% to low 40% range.
Even worse for Landrieu, when voters are asked if they plan to vote for Landrieu in the run-off, she trails Cassidy by between three and nine percent.
Robert Hogan, a political science professor at Louisiana State University, said Landrieu has seen her state rapidly trend more Republican since she won the seat for the first time in 1996, and says a run-off may be one step too far for her.
"I think that her support is probably around 42 or 43 percent," Hogan said.
The runoffs will be even more crucial if the results determine control of the Senate. Such a scenario would unleash a torrent of national attention, campaign cash and duels by top party surrogates, which could produce cliffhanger election nights weeks after voters go to the polls in November.