Spoiler alert: As both Democrats Republicans calculate their odds of a Senate majority, several third party candidates are complicating their math.
Popular dissatisfaction with both parties — and bitter campaigns that are driving up candidates’ negatives on both sides — have helped boost third-party candidates in a number of states into the high single digits.
But there are precedents.
National Democrats quietly sent mailers boosting Montana Libertarian Senate candidate Dan Cox in 2012. He pulled nearly seven percent of the vote as Sen. Jon Tester (D-Mont.) defeated Rep. Denny Rehberg (R-Mont.) by just four points.
Voters in Virginia’s 2013 gubernatorial election were disgusted with both major-party candidates, especially with Republican Ken Cuccinelli. As a result, libertarian Robert Sarvis took seven percent of the vote, and now-Virginia Gov. Terry McAuliffe (D) won by less than three points.
Then-Republican Florida Gov. Charlie Crist’s decision to bolt from the GOP and run as an independent Senate candidate in 2010 badly divided the state’s Democrats, giving now-Sen. Marco Rubio (R-Fla.) an easy path to victory.
It’s unclear whether any third-party candidates will throw an election one direction or the other this cycle. But strategists in both parties are keeping an eye on them.
“We're talking about eight or nine races out there that could potentially be within the margin of error,” said GOP strategist Ford O’Connell. “In most cases a third-party candidate is probably not helpful to the Republican Party but there are a few places where it's been a benefit,”
Here are six races where third-party candidates could have a real impact on the election.
The Tar Heel State is similar to last year’s Virginia race — tons of negative advertising and two unpopular candidates, opening the door for a protest vote.
Enter Libertarian Party nominee and pizza delivery man Sean Haugh, who despite almost no money has been pulling between 8 and 12 percent in most public and private polls.
North Carolina House Speaker Thom Tillis (R) may be able to pull some of those votes back from Haugh if he can unite a GOP base still somewhat split after the May primary. But Haugh is currently providing a home for some unhappy Republicans and right-leaning independents, making it harder for Tillis to catch up to Hagan, who’s had a lead in most recent polling.
“In North Carolina [Haugh] could matter,” admitted one national Republican. “There are a lot of folks that haven't come around, they're still harboring ill will from the Republican primary and maybe haven't come around to Tillis yet. That doesn't mean that they un-persuadable though.”
The presence of Tea Party candidate Rob Maness (R) and a Libertarian Party candidate have made it likely that the election won’t be decided in November’s all-party contest but instead in a December runoff that could be harder for Sen. Mary Landrieu (D-La.) to win.
Democrats still believe Landrieu could pull off an outright victory, though acknowledge that’s an uphill battle. Most polls put her in the mid-40s, with Rep. Bill Cassidy (R-La.) close behind. Republicans admit the crowded race means that Cassidy will have to win in December, and have already begun reserving airtime for that month.
Landrieu has won runoff elections in the past, but this year could prove harder, especially if the race will determine Senate control, making it easier for Republicans to nationalize messaging.
“With Georgia and Louisiana, it makes it tougher to get to 50 percent. The sky is also blue,” said one national Democratic strategist.
Like Louisiana, Georgia is a runoff state. If the race does go until January, Democrats concede it might be harder to turn out African Americans at high enough levels to push former charity executive Michelle Nunn (D).
Nunn has been trailing businessman David Perdue (R) in most recent public polls, and Republicans are confident that even if she forces a runoff they’ll hold the upper hand. Recent polling has also shown Libertarian Amanda Swafford in the high single digits, making it harder for Nunn to get to 50 percent.
“In Louisiana and Georgia, the third-party candidates have a huge opportunity to make an impact because they can literally change the course and timing of the election. They're changing the vote necessary to win, but they're actually raising rather than lowering the threshold to victory,” said Rothenberg Political Report deputy editor Nathan Gonzales.
Republicans dodged a bullet when 2010 candidate Joe Miller (R) announced this week he’ll endorse Tuesday’s primary winner, ruling out a third-party bid that could have undercut the GOP nominee.
But even without Miller on the ballot, his friend and Libertarian Party nominee Mark Fish will be, as will an Alaskan Independence Party candidate. Third party candidates often do better than they do in Alaska than they do in other states, and at times have siphoned off GOP votes. In what could be a razor-tight race, a few thousand votes here or there could make a difference.
“Begich's path to victory gets significantly easier the further below 50 percent he can win with, and a bigger combination of candidates helps him do that,” said Gonzales.
Republicans were already in good position in this open seat race when Democrats failed to recruit a top-tier candidate. But the nail in Democrats’ coffin came when former GOP Sen. Larry Pressler’s decided to make an independent bid, and pivoted to the center-left to do so.
The few public polls of the race indicate that Pressler and Democratic candidate Rick Weiland are splitting Democrats and independents, giving former Gov. Mike Rounds (R) a huge lead.
“Even without Pressler it would have been hard. But he's pulling the people we would have needed to have a shot,” admitted one national Democratic strategist.
The grudge match between Senate Minority Leader Mitch McConnell (R) and Kentucky Secretary of State Alison Lundergan Grimes (D) has a third player — Libertarian police officer David Patterson, who recently filed the necessary signatures to get on the ballot.
Patterson has pulled above five percent in a few polls -- more than the difference between the two candidates -- though strategists in both parties say they’re unsure who he’ll hurt in the race.
Some Patterson support is likely coming from Tea Party-leaning voters who don’t think McConnell is conservative enough. But some Democrats worry that if McConnell does enough damage to Grimes’s favorability, some who might be looking to vote for anyone but McConnell will vote for Patterson instead.