As Americans go to the polls in a presidential election featuring the two most unpopular candidates in recent memory, the option of casting a vote for a third-party candidate may be a real consideration for many. Barring a stunning development that would top anything that even this most unpredictable of election cycles has so far thrown up, a third-party candidate will not be winning the keys to the White House on Tuesday. However, they could still have a significant say in Donald Trump’s and Hillary Clinton’s hopes of being the next president.

Libertarian Party candidate Gary Johnson is polling at 4.8 percent heading into the election. And, while that may not seem like much, with the vote on a knife edge in Florida, even a small number of votes for Johnson, or Green Party candidate Jill Stein, could have a major impact. It would certainly not be the first time that a third-party candidate has played spoiler to a major nominee’s hopes.

Ralph Nader – 2000

The mere mention of Ralph Nader’s name still sends shivers down the back of many Democrats. Although he won only 2.7 percent of the nation vote, the Green Party candidate amassed close to 100,000 votes in Florida. That number is a big one when considering the official count had Republican George W. Bush beating Democratic rival Al Gore by just 537 votes when a recount was halted by the Supreme Court. Many Democrats remain steadfast in their belief that Nader effectively cost Gore the election, although the Green Party continues to rally against that notion to this day.

Ross Perot – 1992

Running as an independent in the 1992 election, the Texas businessman didn’t get a single electoral vote. He did, however, get just under 19 percent of the popular vote, making him still the most successful third-party candidate since 1912. There was much conjecture that Perot had played a part in helping Democrat Bill Clinton beat his Republican opponent George H.W. Bush. However, evidence that he drew support away mainly from Bush is sketchy. Perot ran again four years later, that time under the umbrella of the Reform Party, but his support slipped to 8 percent nationally.

gary johnson for prez Libertarian presidential candidate Gary Johnson speaks at a rally in New York, Sept. 10, 2016. Photo: REUTERS/Mark Kauzlarich

George Wallace – 1968

A former Democratic governor Alabama, Wallace ran as the candidate for the American Independent Party in 1968 on a pitch of social conservatism and pro-segregation in the South. Wallace is still the last candidate from outside the two main political parties to win an electoral vote, taking 46, all in the South. His policies meant that, if anything, he was a threat to Richard Nixon, something the Republican candidate made clear during the campaign. Yet Nixon still ended up winning a landslide against Democrat Hubert Humphrey.

Theodore Roosevelt – 1912

President from 1901 to 1909, Roosevelt came back to run in the 1912 election after becoming disillusioned with Republican Party nominee William Howard Taft. Having been denied the Republican nomination, he opted to run as a third-party candidate for the Progressive Party, nicknamed the Bull Moose Party. While he didn’t win, Roosevelt effectively split the Republican vote, garnering 27 percent of the vote and pushing Taft into third place, allowing Democrat Woodrow Wilson to take the presidency.