There are not enough born again Christians in America to win an election on their own. Not enough secular Christians, so-called conservatives or others would join together with born again Christians to support a third party that was truly Christian in standards.
Not voting for certain candidates or positions is a viable option. If one is facing a choice on a ballot between a really bad candidate and an even worse candidate, it's a viable option to vote for neither in that category and go on to the next section of the ballot.
The primaries is where Christians could have a strong voice. Even though the powers that be try to limit the choices even in primaries, there is at least usually some candidates who aren't totally sold out in the running. However, Christians, conservatives and others continually fail to take advantage of the primaries, which allows the party powerful to promote their own and the more "moderate" and liberal portions of the Party, with media support, to determine who the candidate will be.
If nothing else, the Ron Paul supporters showed how a small but determined group can effect big results. This even to the point where the Party machine used manipulation and outright tampering to curtail the positive impact such was having for the Ron Paul candidacy.
Meanwhile, Christians were fickle and without any sense of loyalty or purpose. They flocked first to Bachmann, then at the first sign of bad press dropped her for the next in line, until some bad press caused them to scatter like rats from a burning building to the next, then the cycle kept repeating itself until we ended up others choosing the candidate. Thus at the end of the last two presidential primaries we had left leaning, big time compromisers as the candidate.
What might happen if Christians were to engage in long term, concerted, consistent direct prayer regarding candidates and coming elections years before the elections rather than just putting forth a general call for prayer at the last minute?