What would a third party need to do to win national elections

A third party winning the national election in the United States is a near impossibility. The Republican and Democratic parties are so exceptionally well organized after over 150 years of experience that they defeat any third party. The lack of organization is in fact the number one reason the Independent Party never wins. Another aspect of this is media attention; the biggest media sources seen by the common people only cover the candidates from the aforementioned Republican and Democratic parties. The final aspect is what is known as the Spoiler Affect; the better a third party does, the more he hurts the party most closely affiliated with him, as this splits the vote. A classic example of this is the 1912 election, in which 60% voted Republican, but this was split between two different branches of the Republican party, while only 40% of the population voted Democrat, but since the Republican vote was divided, the Democrat won by a large margin.