The most newsworthy presidential candidate at the moment is one who wasn’t on the ballot in the Iowa caucuses — Michael Bloomberg.

Pollster Frank Luntz, who worked for Mr. Bloomberg’s successful New York City mayoral campaign in 2001, is out with a nationwide poll of 900 likely voters. He describes the poll as showing that if Mr. Bloomberg runs, he can actually win.

“Bloomberg would be a serious contender the moment he announced,” Mr. Luntz wrote in a memo with the poll results, which show Mr. Bloomberg within reach of Hillary Clinton and Donald Trump without having done any campaigning or having spent a penny on political advertising.

Mr. Bloomberg’s poll numbers have room to grow. A recent Franklin Pierce University/Boston Herald poll of New Hampshire voters found “Most Democrats have no opinion about him (44 percent) or have never heard of him (7 percent).”

Analysis purporting to show that there is no ideological room in the race for Mr. Bloomberg is flawed. For example, Nate Silver, writing at Fivethirtyeight.com, claims that Mr. Bloomberg “now holds positions that, while rightward of Sanders’s, aren’t appreciably different from Barack Obama’s or Hillary Clinton’s.”

Mr. Silver may not be able to appreciate the differences between Mr. Bloomberg and Mrs. Clinton. But here are a few big ones. Mrs. Clinton, in a pander to unions and the left-wing Democratic primary electorate, opposes the Trans-Pacific Partnership trade deal. So, by the way, do Donald Trump and Ted Cruz. Mr. Bloomberg is for the deal, for reasons outlined in this excellent Bloomberg View editorial.

Mrs. Clinton opposes the Keystone XL oil pipeline — again, in a pander to the left-wing Democratic primary electorate. Mr. Bloomberg is for the pipeline, for reasons outlined in this Bloomberg View editorial.

Hillary Clinton has not spent a lot of time on the campaign trail talking about education reform. But the teachers’ unions — in particular the American Federation of Teachers and its president, Randi Weingarten — have been part of the backbone of her campaign. So have other public employee unions.

Mr. Bloomberg, who took a tougher line in negotiations with the public employees as mayor of New York and who was a leader when it came to charter schools and educational accountability, would almost certainly come down closer to Jeb Bush than to Mrs. Clinton on education reform.

What’s more, the case for Mr. Bloomberg rests not merely on his positions, but on his accomplishments. He would be the only candidate in the race with genuine achievements at the executive level in both the private sector and the public sector.

Unlike Mrs. Clinton or Senator Cruz, he built a successful, high-technology, global business. Unlike Mr. Trump, he has been elected and re-elected to public office. While Mrs. Clinton’s public sector executive accomplishments are open to question — she’s probably best known for the Benghazi attack and her private email server — Mr. Bloomberg can reasonably claim credit for New York City’s phenomenal comeback following the terrorist attacks of September 11, 2001. As mayor, Mr. Bloomberg worked well with both Republicans such as George W. Bush and Governor Pataki, and Democrats, such as Senator Schumer and City Council Speaker Christine Quinn.

In the past, Mr. Bloomberg has been privately skeptical about the public’s openness to voting for a divorced Jewish billionaire. The tens of millions of Americans rallying behind Mr. Trump, who is a billionaire, and Senator Sanders, who is Jewish, should be reassuring on those fronts. Both Messrs. Trump and Sanders are also divorced, though, unlike Mr. Bloomberg, they remarried.

I followed Mr. Bloomberg closely between 2002 and 2008, when he was mayor of New York and I was managing editor of The New York Sun. He sometimes disappointed me, and I certainly did not always agree with him or his administration.

The Bloomberg move that really won me over came after he was done being mayor, in July of 2014, with Israel under attack by rockets from Gaza. The Obama administration’s FAA slapped a ban on commercial flights to Israel by American carriers, striking a blow at Israel’s economy.

Mr. Bloomberg issued a statement: “This evening I will be flying on El Al to Tel Aviv to show solidarity with the Israeli people and to demonstrate that it is safe to fly in and out of Israel. Ben Gurion is the best-protected airport in the world and El Al flights have been regularly flying in and out of it safely. The flight restrictions are a mistake that hands Hamas an undeserved victory and should be lifted immediately. I strongly urge the FAA to reverse course and permit US airlines to fly to Israel.”

The FAA — also under pressure from Senator Cruz — promptly reversed the ban. What a gutsy move by Mr. Bloomberg.

People know Mr. Bloomberg as an entrepreneur, and perhaps as an ego or an elitist. The part that often is forgotten is that he is an Eagle Scout. On that list of Boy Scout qualities — “trustworthy, loyal, helpful, friendly, courteous, kind, obedient, cheerful, thrifty, brave, clean, and reverent” — brave counts for a lot. It explains that commercial flight to Tel Aviv, and it suggests to me that this time around, Mr. Bloomberg just might get into the presidential race.

Mr. Stoll is editor of FutureOfCapitalism.com.