The only way someone with the solidly conservative ideology like Duncan Hunter or Tom Tancredo could win is if one of them ran for President as an independent, Giuliani or McCain received the GOP nomination, and Bloomberg ran as an independent. Since the major party nominations will probably be decided by St. Valentine's Day, rather than May or June, there is a lot more time to raise funds and enlist volunteers. An independent conservative would not have the funding of the two major parties and Bloomberg, but would make up for it through the Internet and bloggers. Center-right talk show hosts and GOP politicians would have a difficult time keeping the conservative voters on the Republican plantation and some would likely defect to the independent run. I could easily see Neal Boortz, Michael Savage, and Ann Coulter enthusiastically supporting an independent, and Rush Limbaugh and Sean Hannity defecting from the GOP if the independent conservative is running strongly.
Winning the Presidency with 30-35% of the national popular vote would be unprecedented, as even Lincoln won 39.8% of the national popular vote in a four way race in 1860. Wilson received 41% of the national popular vote in 1912, and Clinton received 43% in 1992. But it is not implausible, as the numerous conservative constituencies already dislike Giuliani and McCain, and would defect to a viable independent conservative.