Is there ever a good reason to vote for a third party? Why or why not?
There are several answers to this question.
First, the short answer. "Is there ever? Yes."
Then there are the slightly longer standard answers -- which basically means they answer the second half of the question. They go something like "Yes, if you're just trying to make a point" and "No, not if you want to accomplish anything."
Then there are long and detailed explanations and rationalizations and debates and arguments and all that good stuff. Hopefully this post will be somewhere in between the "slightly longer" and the "very long."
Is there ever a reason to vote for a third party? Yes -- there are many. You like the third-party candidate, they line up with your positions on important issues better than the major-party candidates, the third-party candidate is your (hopefully) future father-in-law, you can't stand the two-party system, or you felt like bucking the trend and writing in the Justice Party's candidate for President. All of these are potential reasons for vote for a third-party candidate -- albeit with varying degrees of validity.
So having covered some potential reasons to vote for a third-party candidate, let's explore a real-life scenario. The most common objection to voting third-party is that "you're throwing away your vote." This objection again has varying degrees of validity depending on the situation. For example, if you have a Republican candidate for Sheriff who supports banning all guns, and the Democratic candidate for Sheriff also does, and you realize that the bad guys won't follow this gun ban and all it will really do is leave you defenseless, well then you may want to seriously consider voting for the Constitution Party candidate who happens to own the gun store down the street and also served with the U.S. Marines in Iraq. On the other hand, if the Republican candidate supports your constitutional right to keep and bear arms, the Democratic candidate supports a gun ban, and the Constitution Party candidate still decides to get into the race, you probably won't accomplish as much by voting for the Constitution Party candidate. At best, you likely voted for a losing candidate, at worst, the conservative vote is split between the Republican and Constitution Party candidates,and the Democrat wins the race.
Now this example is over-simplified. Most likely, there are more disputed issues in this race than just gun bans. For instance, the Republican might be pro-life, the Democrat pro-abortion, and the Constitution Party guy doesn't care. Are you willing to vote for someone who says they "don't care" about defending the defenseless, even if they are the only one supporting your second amendment rights? This is just a small example of how these decisions can become more and more complex as you dig deeper into the views and positions of the competing candidates.
In conclusion, yes, there are some reasons that you may end up voting for a third-party candidate. Realistically, however, if you are seeking to protect and advance faith, family, freedom, and opportunity in American by making your voice heard in the political process, you won't likely end up casting too many votes for a third party -- and least not at this point in history.