He also noted that he'll appear on ballots alongside President Obama and Mitt Romney in all 50 states in November.
"Lots of opportunity to change the world a little bit," he said, describing his campaign. "I have seen nothing but increased crowds, increased appetite for what I have to say."
Comedy Central host Jon Stewart described being a libertarian as two halves of a friendship necklace — half Republican, half Democrat, according to the policies that traditionally appeal to each part — coming together to make a whole heart. Johnson agreed.
"A libertarian candidate's going to come at Obama from the left and come at Romney at the right," he predicted. Johnson, cautiously optimistic about his chances as a third-party spoiler in November, said more people are willing to consider voting for a third party in 2012 than ever before.
"There are more libertarians, people who declare themselves libertarian, than vote for a libertarian candidate," he said.
Johnson, the former Republican governor of New Mexico, dropped his bid for the Republican presidential nomination late last year in favor of running as a libertarian. He became the official third-party nominee in May and became eligible for federal matching funds last week.
But Johnson also credited Rep. Ron Paul (R-Texas) for standing for libertarian principles as a GOP presidential candidate. He endorsed Paul's bid for the presidency in 2008 and backed him for 2012 GOP Iowa caucuses shortly after dropping his own GOP bid.
"I'm delivering a message of liberty and freedom very much along the same lines as Ron Paul," he said. "I don't think Ron Paul's going to be successful winning the [Republican] nomination. I wish him luck. So that message goes away when his candidacy comes to an end."
Paul stopped competing in the primaries in mid-May, although he has not officially suspended his campaign. Romney has won enough delegates to cinch the nomination.