I love Ron Paul, but he is completely unelectable. Candidates need to be able to play the wings and idealogues to garner base support in the primaries, then miraculously move to the center in the general election to get elected. Ron Paul will never find a way to the center.
Newt? Not a chance. Most people with memories of the 90's will never forgive him for single-handedly turning the US government into the laughing stock of the world, and creating the bitter partisan rhetoric that's been the national anthem for the past two decades. Numerous government shut-downs for political posturing, partisan impeachment of a sitting president over an affair. I'm sure there are plenty of powers in Washington that would love to see Newt come into power, just so they can torture him, but it absolutely won't happen.
No president gets elected (for the first time) in this day and age without looking like a shiny penny, and the luster left Newt decades ago.