Of course, as every poll-watcher knows, Haugh is almost certain to earn a smaller share of the vote on Election Day. But Libertarians have been playing a bigger role in recent years, often to the detriment of Republicans, and it's not unreasonable to imagine Haugh could pull down 5 or 6 percent of the vote. In Montana's 2012 Senate race, for instance, a Libertarian took 6.6 percent, far in excess of Jon Tester's 3.7 percent margin of victory. And last year in the Virginia governor's race, Libertarian Robert Sarvis captured 6.5 percent—again, much more than Terry McAullife's final 2.5 percent win.
And PPP's numbers do indeed demonstrate that Haugh is hurting Tillis more than Hagan. When Haugh's supporters are re-allocated based on which candidate they lean towards, Tillis moves into a 41-41 tie with Hagan. That could make all the difference in a close race, as this one seems apt to be. What's more, as Tom Jensen points out, the undecideds actually are a Dem-leaning group. They went 55-37 for Obama, which is unusual in a red state. So Tillis can't simply expect to hoover these voters up—he'll actually have some persuading to do. And given how far he lurched to the right to win the GOP primary, that may not be so easy.