Howard Schultz, who turned Starbucks into an international hot-beverage behemoth, is brewing up a possible run for president, and, no, that’s not the last bad coffee pun you will hear between now and when he decides.

The Seattle billionaire announced he was exploring a possible 2020 run as an independent, casting himself as an alternative to the two major political parties, which he depicts as cause and beneficiaries of a failed system of “infighting and self-interest” that has starved the country of leadership.

President Donald Trump responded with a tweet egging Schultz into the race by claiming he “doesn’t have the ‘guts’” to seek the White House. Democrats and their allies were apoplectic. “Don’t help elect Trump, you egotistical billionaire a–hole,” a heckler shouted at a New York City book signing, articulating a concern others share and doing so with particular vehemence and profane vernacular.

Combined, the reaction underscored the conventional wisdom — for what that’s worth — that Schultz’s candidacy would most likely siphon votes from Democrats’ eventual nominee, ensuring Trump a second term.

Q: Is that why Schultz is thinking of running?

A: He insists not. A professed Democrat his whole life, Schultz, 65, has harshly criticized Trump, calling him “unfit for office” and stating he would not do “anything to put Donald Trump back in the Oval Office.”

One has to presume if the former Starbucks chairman and chief executive runs, he hopes to win the White House.

Q: So what are the chances?

A: Negligible.

No third-party or independent candidate has ever been elected president. The most successful was Theodore Roosevelt, in his 1912 political comeback bid. The former two-term president, running as the candidate of the splendidly named Bull Moose Party, received 27 percent of the vote and 88 electoral votes, good enough to finish second ahead of Republican President William Howard Taft and tip the race to Democrat Woodrow Wilson.

Q: Will Howard Schultz run under the banner of some shaggy mammal?

A: Alas, probably not.

Q: Why do third-party candidates face such steep odds?

A: There are structural reasons. Laws restricting ballot access and helping perpetuate the two-party system can pose a formidable challenge, albeit one that Schultz, who is worth an estimated $3.4 billion, could presumably overcome with enough legal firepower and on-the-ground organization.

Another reason — perhaps more formidable — is partisan loyalty. Although it’s fashionable to assert one’s political independence, the truth is most voters are faithful to one or the other major political party, even if they choose not to identify themselves as Democrat or Republican. True independents who vote Democratic, Republican or third-party depending on the election may constitute as little as 5 percent of the electorate.

Among partisans, which is to say most voters, the overwhelming majority end up supporting their party’s presidential nominee, notwithstanding all that grumbling about lesser of evils. In fact, party labels are the single best predictor of voting behavior, a better forecaster than age, income, gender, education, sexual orientation or whether someone lives in a city, the suburbs or rural America.

Q: What about the prospects of tipping the election?

A: That’s always a possibility, though it may be somewhat exaggerated.

Some Republicans assert that Ross Perot, who won 19 percent of the vote in 1992, put Democrat Bill Clinton in the White House by taking votes away from President George H.W. Bush. But that fails to bear up under careful study.

A case could be made that Ralph Nader cost Al Gore the presidency by peeling off votes in Florida, which Republican George W. Bush carried by 537 votes to win the White House (thanks to an assist from the U.S. Supreme Court). Nader, running to Gore’s left, won more than 97,000 votes in the state.

Some Democrats also point to Michigan, Pennsylvania and Wisconsin, which elected Trump president, and note his margin against Hillary Clinton in 2016 was less than the vote received by third-party candidates. That, however, assumes the bulk of those votes would have gone to Clinton, which is more clairvoyance than political science.

Q: So when will Schultz decide?

A: Bill Burton, a former White House spokesman for President Barack Obama who has signed on as a strategist for the maybe-campaign, said the coffee mogul would make up his mind sometime in the summer or fall.

Burton suggested nothing was certain. “He’s just asking the question of whether or not there’s an appetite out for there for another choice that is not the nominee of either party,” Burton said. “We’ll find out the answer to that question over the course of the next several months.”

Q: There’s a latte to consider!

A: Please.

Q: Given history, Schultz’s candidacy seems like a waste of time and effort.

A: Not necessarily. Even if he fails to win the White House — and who the heck knows — he could help shape the debate and maybe influence the policies pursued by whoever gets elected in 2020.

Perot, for instance, took deficit reduction, a pet obsession, and helped make it a driver of policy in the Clinton administration, which produced, in tandem with a GOP-run Congress, the first balanced budget in generations.

If Schultz “has a particular policy he wants to pursue, it might be worth the effort,” said Daniel Franklin, a professor of political science at Georgia State University. An expert on third parties, Franklin noted Perot spent tens of millions in pursuing the White House and, in the process, made the national debt a part of the political conversation.

On the other hand, Perot’s vivid description of a “giant sucking sound” of American jobs heading south of the border failed to derail the NAFTA trade agreement with Mexico and Canada.

Q: What issues would Schultz run on?

A: That remains to be seen. Given how he’s assailed Sens. Elizabeth Warren of Massachusetts and Kamala Harris of California over raising taxes on the rich and vastly expanding Medicare, respectively, it seems likely he would marry fiscal conservatism with a more centrist stance on social issues and the environment.

Q: That could be grounds for a campaign.

A: Stop. Just stop.