As one on the opposite side mentioned, "No Third Party Stands a Chance". This isn't necessarily about a third part, but a single individual; a centrist. Moderatism ensures the rights and interests of everyone. With conservatives and liberals, they reject nearly every ideology and opinion of the opposite side and that creates unnecessary tension. For example: Conservatives would try to make abortion illegal which would be harmful and inconsiderate to the women who actually NEED it and liberals (as they already have) legalised gay marriage across the country without the consent of every state, this means that the opinions of the citizens of states who voted AGAINST gay marriage are now worthless. And though either side might be celebrating for these examples, it would always leave the opposing side feel worthless. A good centrist tries to appeal both sides and works to bring the two together by finding similarities in beliefs and structures through simple logic and information.
If anyone else here identified as a centrist politically you know how frustrating campaign years are. Candidates on both sides leaning further left or right to get the nomination and leaving centrists like myself reaching either direction trying not to tip over while sitting on a stool. Moderates on both sides are harder and harder to come by but it seams that there are many in the same boat as me. If a candidate where to wall right down the line and had respectable character they would have my vote. If you aren't sure where you fall I suggest talking the quiz at Istandwith.Com it might help you figure it out.
Thanks to our seriously jacked up two party system, the odds of any third party candidate (independent, green, libertarian, constitution, etc) are so slim they might as well not even bother. The highest possible position for a third party candidate is US Senator, nothing higher than that is even remotely achievable.