Dana Perino is a useless tool of the Bush dynasty. Whoever will run third party will need a ton of money for - apart from anything else - there is no party apparatus for a non existent party. Presidential elections are state-run elections. You have to have an apparatus in every state to get your name out. The RNC and DNC have offices, staff, and a whole host of things like that in multiple locations within each state to coordinate messaging - and those offices stay open all year long. Good luck to a 3rd party candidate who has to rely on Other People’s Money to setup a network like that, especially at this late stage.
The thrid party candidate doesn’t need to win the election. Just disrupt it enough to allow the Dem to win. I don’t think it takes many resources. Look at how many votes the Ron Paul/Gary Johnson 3rd party plays in 2012. Enough to make a significant difference (despite Romney’s low appeal w Conservatives).
The Libertarian Party is the best bet for someone like Rand Paul whose father ran as a candidate for President on the Libertarian ticket in 1988.