A Republican comes within a hair’s breadth of winning a Senate seat — only to lose when the Libertarian Party candidate draws more votes than difference between the majority-party candidates’ numbers. Elsewhere, a Democrat is narrowly defeated when a Green Party candidate takes a few percentage points in a tight race where the Republican has less than a single point’s lead. These scenarios have played out a several times in recent elections, including on Tuesday. Only in the past 24 hours has Kyrsten Sinema, the Democrats’ candidate for Senate in Arizona, pulled ahead of her Republican rival by half a percent, as votes continue to be counted. The Green Party candidate in that race won 2.3 percent.

The lesson is obvious: third parties are nothing but spoilers and detrimental to the very causes they purport to champion. If there were no Libertarian candidates, Republicans would do much better. And if it weren’t for the Green Party, Al Gore instead of George W. Bush would have been president after the 2000 election. Ralph Nader, the Green candidate in 2000, received nearly 2.9 million votes nationwide. Those could have been the deciding votes of the election — and they arguably were.

There’s a pure righteous anger directed at third parties just now — from Republicans who think that some of last Tuesday’s losses would have been wins if only there hadn’t been a Libertarian on the ballot; and from Democrats who view every Green Party candidate is another Nader, a coalition-breaker who clears the path for Republican victory. Don’t the naifs who vote for these hopeless third parties appreciate the stakes?

They probably do — they just don’t care. Or rather, they care in ways that major-party voters seem habitually incapable of understanding. Libertarians are not just confused Republicans; Greens are something more than unrealistic Democrats. And quite often the major party that to an outsider seems closes to a third-party voter’s ideals is the one that voter abhors the most.

Green Party voters are Greens because they are not Democrats, just as Libertarians are not Republicans. A third-party vote is a way of registering disapproval toward both major parties, but especially the party that might in theory be second-closest to the voter. A Green may hate the Democratic Party even more than the Republican Party for being a corruption of an ideal, and a roadblock to the emergence of any stronger left-wing politics in this country. Libertarians in some cases are Libertarian Party voters because they are social liberals who find the Democratic Party’s identity politics and statist economics repellent. But many other Libertarians are anti-Republicans because they despise GOP statism even more the Democratic variety. Polls of Libertarians taken in 2016 found a roughly 50-50 split for second choices among the major parties.

It’s not a safe assumption to say that if there were no independent options, third-party voters would overwhelmingly choose to support the major party they’re ‘supposed’ to prefer. The third-party vote would divide among the two major parties — that is, the part of the vote that was still case in such a scenario would divide. Many third-party voters, deprived of the chance to cast a ballot against the majors or for a small party in which they actually believe, would rather stay home than choose a lesser evil to support.

That stay-at-home vote is far more significant to any election than the third-party vote. Even with half-century record turnout in Tuesday’s midterms, most states did not see even half of their eligible voters go to the polls. The pool of non-voters absolutely dwarfs the ranks of third-party voters. Much greater electoral gains can be had by drawing some of the former to the polls than by browbeating the latter for ‘wasting’ their votes.

The onus is on politicians, not voters, to bring out the numbers they need to win. A major-party candidate who suffers from a third-party alternative being on the ballot is someone who has failed to make the sale to potential buyers — and such a failure with regard to the people who cast their ballots for third-party candidates is sure to be echoed by a failure with regard to people who aren’t motivated to go to the polls at all.

The Trump-Clinton race of two years ago was an excellent illustration of how little difference third parties and independent candidates make. Gary Johnson won nearly 4.5 million votes, a record for the Libertarian Party — yet that didn’t dent the electoral map majority Donald Trump pulled together. Independent neoconservative candidate Evan McMullin was likewise barely even a blip. Not only Republicans, but independent, libertarians, and voters of all description who either supported Trump or rejected Clinton were taking no chances with symbolic or expressive voting. They backed the Republican nominee.

Whether the Libertarian or Green parties serve any constructive purpose, beyond simply acting as steam valves for their very few voters, is a separate question. But they are not wreckers of the major parties’ fortunes. Most of the time, a Republican or Democrat can wreck himself (or herself) without a minor party’s help.