Here are the current poll numbers for Libertarian Gary Johnson compared to the respective leads for either Obama or Romney in several states:
Ohio: after the outlier 10.6% showing for Johnson in an earlier poll, CNN shows him now at 3%, which exactly covers the difference between Obama and Romney.
Pennsylvania: Obama's lead over Romney has shrunk to 2%; Johnson is currently polling at 3%.
Colorado: Obama leads Romney by a razor thin margin of perhaps 1%; Johnson is currently polling at 7%.
Nevada: Obama leads Romney by 4.6%; Johnson is currently polling at 3%.
New Hampshire: Obama leads Romney by 6%; Johnson is currently polling 7%.
Virginia: Obama leads Romney by 1-2%. Johnson is currently polling 4%.
Wisconsin: Obama leads Romney by 6.6%. Johnson is currently polling 6%.
In North Carolina and Florida the polls so far do not include Johnson, but in Florida where he is the only other name on the ballot, the polls shows show the race between Obama and Romney virtually deadlocked, with about 8% preferring "someone else." In North Carolina the polls show the Romney/Obama difference at about 1% either way; Libertarian candidates in NC in 2008 picked up more than 3% of the vote.
1. Johnson right now is threatening Mitt Romney more than Barack Obama; his numbers are not fading a month out from the election, but holding steady in the 3-4% range.
2. Statistically, with 10 states in potential "spoiler" play (and I haven't counted Oregon or New Mexico), there are very good odds that his vote on November 6 will tilt the election one way or the other.
3. The Johnson campaign must grow the vote by another 1-2% before election day. 3-4% will spoil some states, but 5% is necessary to qualify for Federal matching funds in 2016.