I wrote this reply to a guy who was tempted to vote Third Party.
Food for thought:
In 1992 and 1996, a third-party candidate, Ross Perot, split the conservative vote and gave us 8 years of Bill and Hillary Clinton, elected on a mere plurality.
A president must have support in Congress to get anything done. Look at how purposely obstructive Democrats in Congress have stonewalled Social Security reform, approval of judicial appointments, etc., throughout the Bush Administration. No third party has exercised significant power in Congress in modern times.
Chances of electing a third-party president are infinitesimal. A third-party or write-in vote would be wasted, and help elect a Liberal.
It is crucial, due to the history of liberal judicial activism in the Supreme Court, that all future appointments be conservative, or at least holding to the original understanding of the Constitution.
1. Put pressure on McCain to commit to specific conservative positions, in spite of his own inclinations.
2. If you cannot vote FOR McCain, then at least vote AGAINST a liberal, i.e., any and all Democrat candidates.