That’s what Bruce Bartlett argues in this essay at Human Events:
The basic problem with the Libertarian Party is the same problem faced by all third parties: It cannot win. The reason is that under the Constitution a candidate must win an absolute majority in the all-important Electoral College. It won’t do just to have the most votes in a three- or four-way race. You have to have at least 270 electoral votes to win, period.
Theoretically, this is no barrier to third parties at the state and local level. But in practice, if a party cannot win at the presidential level, it is very unlikely to achieve success at lower levels of government. In short, the Electoral College imposes a two-party system on the country that makes it prohibitively difficult for third parties to compete.
On the whole, I think Bartlett is correct. Like it or not, the political system that the Constitution, and our history, has created overwhelmingly favors a two-party system to such an extent that truly successful third-parties have only arisen in situations where one of the two main parties was in a state of crisis.
The Whig Party came out of the ashes of the Federalists. The Republicans arose in part from the ashes of the Whigs. Apart from that, there has been no third-party that has been anything other than a flash-in-the-pan. Had Teddy Roosevelt defeated Woodrow Wilson in the 1912 election, it’s likely that the Progressive Party a/k/a the Bull Moose Party would have supplanted the Republicans, but, other than that, there has been no serious challenge to the two-party system since the 1860 Presidential Election. That’s 146 years folks.
Bartlett goes on to point out something that has been my pet peeve for years. Even when it gets media attention the Libertarian Party seems to blow it. The reason for that is that, quite honestly, the LP is often the haven of gadflys. With the exception of Ron Paul, who returned to the Republican Party, I don’t think I can name one Libertarian Presidential Candidate that I can honestly say would have been qualified to fill the office he was running for.
So, if not the Libertarian Party, then what ?