"He's going to be a problem for somebody, somewhere"

As for which candidate Johnson benefits, it’s unclear. The Libertarians think he mostly takes away from Romney’s numbers. And they say Johnson will likely have the biggest impact in Colorado, based on a recent statewide poll that shows him with 7 percent of the vote.

However, the Aug. 8 survey by the Democrat-leaning Public Policy Polling also suggests Johnson could in fact hurt Obama in Colorado. The survey found Obama leading Romney 49-43 percent, but his lead was cut to 46-42 when voters were given the Johnson choice.

“He’s going to be a problem for somebody, somewhere,” political strategist and Fox News contributor Joe Trippi wrote last month. “We don’t yet know which candidate he might harm the most — but both campaigns should be looking over their shoulders at that guy almost nobody is talking about.”