No third party movement has ever bumped one of the two major parties out of the running in a presidential election…but third parties can wreak havoc under the Electoral College system.
Under the “winner take all” system used by 48 of the 50 states, the winner does just that, winning ALL of the electoral votes from that state even though they might not have received even 50 percent of the vote. This means that, in order to win any electoral votes, a third party would have to outpoll both of the major parties in that state.
Neither the far-right Libertarian Party, founded in 1971, nor the far-left Green Party, founded in 2001, currently the largest “third parties” in the United States, have ever EARNED a single Electoral College vote. (The Libertarians did get ONE electoral vote in 1972 from a faithless elector but that wasn’t an earned vote.) In fact, neither of these third parties has ever won a congressional seat, nor have they ever won a gubernatorial race. The Libertarians currently have three representatives in state legislatures. The Greens have none.
Since the end of Reconstruction in 1877, a total of 30 Senators, 111 Congressmen, and 28 governors have not belonged to either major party…so it is possible for a third party candidate to win an election, but it doesn’t happen often.
It is virtually impossible for a third party candidate to gain enough momentum to unseat a major party candidate, but third parties can affect the outcome of an election. In 2000, Green Party candidate Ralph Nader picked up enough votes from the Democratic Party in Florida to knock Al Gore out of the running, allowing George Bush to become the 43rd president. In 2016, Jill Stein pulled enough votes from Hillary Clinton to turn the tide in Wisconsin and Michigan. In both cases, Gary Johnson pulled enough votes from Donald Trump to put Clinton within striking distance, only to be thwarted by Stein voters.
The most important reason that third parties cannot win in America is that they don’t have enough voters in their parties. The second most important reason is money. Together, the two major party candidates raised $2.32 billion in 2016. Jill Stein raised $3.5 million in 2016, got 1,457,222 votes and spent $2.40 per vote. Gary Johnson raised $11.95 million, received 4,489,233 votes and spent $2.66 per vote. Hillary Clinton spent around $21.26 per vote while Donald Trump spent just $14.80 per vote, but with combined spending of $2.32 billion, it is pretty obvious why third parties fail. Money.
The takeaway for political activists: if someone wants you to vote for a third party, ask where that party is going to come up with the $1.2 billion needed to fund a credible 50 state campaign. If they hem and haw about, gently guide them to the nearest exit, and lock the door behind them.