Ballot Access
Just so that you'll know that Gary Johnson is on the ballot in 45 states, has submitted signatures in 4 of the other 5, and is collecting in the 5th (Kentucky). Evidently a legal challenge is in process in Pennsylvania.
The five states are: Alabama, Connecticut, Kentucky, Pennsylvania, and Rhode Island.
None of which is in play - sorry, Romney, but you are doomed in Pennsylvania regardless.
Which means, gentle reader, that in every close state, Republicans dissatisfied with Romney (like those Paul delegates that walked out of the RNC) have a Libertarian alternative.
Just as a rough order of magnitude, I'll say Gary Johnson is as much of a problem for Romney as voter suppression is for Obama.