Axios is reporting that last week’s announcement was “partly” a trial balloon. How could it be otherwise? The guy has been floating presidential trial balloons for at least 15 years. And every time the calculus is the same mix of pros with the same insuperable con. He’s a centrist, he has a successful record in NYC, he has all the money in the world to spend.

But he has no real constituency, so he can’t win. In the end, that harsh reality always gets him to back off.

It’ll get him to back off this time too, whether he’s on the primary ballot in Alabama or not.

Sources close to Mike Bloomberg tell Axios that last week’s announcement was partly a trial balloon to gauge interest and preserve the former mayor’s options — but his own very extensive polling remains far from convincing…

Bloomberg, reflecting his life in business, is practical and data-driven. His formal announcement has always been contingent on whether polling showed a convincing path to victory.

Public polling is sparse but Morning Consult delivered some data this weekend. He … does not having a convincing path to victory.

Michael Bloomberg is running at 4 percent nationally as he teases a presidential bid, showing that he’s well known — but widely disliked — by the Democratic electorate, according to a new poll.

No contender is viewed more negatively by Democrats than the billionaire former New York City mayor…

Nearly 25 percent of likely primary voters view him unfavorably — the highest unfavorable rating in the field — while about 31 percent view him favorably, according to the poll.

Despite all the chin-pulling last week about how Bloomberg’s entry might shake up the race, the numbers from Morning Consult show him having no effect on anyone in the top tier. Would Bloomy steal centrist votes from Joe Biden? Nope. Biden was at 32 percent in the previous survey and is at 31 percent now with Bloomberg in the field. How about the two fallback options for centrists in the race, Pete Buttigieg and Amy Klobuchar? Now that Bloomy’s in, is he the new Plan B for moderates? Nope. Buttigieg actually gained a point, from seven to eight percent, and Klobuchar is steady at two percent. But what about Sanders and Warren, the great progressive hopes? Maybe watching a mega-billionaire Wall-Street-friendly squish jump into the race this late will so disgust some liberals that Bernie and/or Warren might see their numbers rise! Nope, not much change there either: Warren is down two points from 20 percent to 18 while Sanders is holding firm at 20.

Bloomberg’s four percent is probably coming from the “none of the above” crowd, the sort of Democratic voter who’s taken a hard look at the top four and decided to go in a different direction or remain undecided for now. Primary voters supporting someone other than Biden, Warren, Sanders, or Buttigieg are around 20-25 percent of the Democratic electorate; Bloomy would be cooking if he could consolidate all of them. But he can’t. There’s not a lot of overlap between Mike Bloomberg and the “Yang Gang” or Tulsi Gabbard’s coalition, I take it. And some supporters of the low-polling candidates are apt to be highly devoted to their choice, which is how they ended up supporting those candidates in the first place. There’s another problem, too: By the time Democratic voters finally have a chance to cast a vote for Bloomberg, the race will have already begun to take shape.

Imagine Bloomberg trying to elbow his way into the Democratic conversation on Super Tuesday if Joe Biden has already put together multiple early-state wins or one of the progressive candidates has surged to surprise victories, with sudden momentum behind them. Bloomy needs a three- or four-way split among the top tier in winning Iowa, New Hampshire, South Carolina, and Nevada so that Democratic voters start panicking about a stalemate and a brokered convention and maybe begin considering compromise candidates. Although even then, I think a three- or four-way stalemate would only harden the resolve of supporters of the top tier and push them to turn out in force for their candidate on Super Tuesday to tilt the balance of power in the race.

The dream scenario for Bloomberg is that either Warren or Sanders wins big in the early states, effectively vanquishing Biden and leaving moderate Democrats terrified that a socialist is about to waltz away with the nomination. With Biden and Buttigieg having already been beaten and Bloomberg advertising aggressively in Super Tuesday states, centrists may decide that uniting behind Bloomy is their last best chance to nominate a moderate instead. We will hear a lot about electability at that point, starting with the latest data from battleground states showing that voters there would prefer a centrist Democratic nominee to a more ideological one. But the concept is flawed, for the same reason that trying to stop Trump in the 2016 primaries after he built up some early momentum was futile. Once populists have tasted real hope for victory with their candidate, watching the establishment unite to squelch him would alienate them so deeply that a critical mass would end up boycotting the general election and sinking the party.

Three years ago, Republicans came to realize that they’d do better with a party uneasily united behind Trump than with a party fractured over Cruz or Rubio. Establishment Dems will reach the same conclusion. They’re better off not rallying against a progressive candidate with momentum from early-state wins than they are getting a more “electable” candidate like Bloomberg nominated. If you thought righty populists would have resented Beltway Republicans for coalescing around Rubio or John Kasich after Trump racked up some early victories in 2016, imagine the left trying to stomach Bernie Sanders or Elizabeth Warren having the nomination plucked from their hands by a billionaire with infinite resources and his many Wall Street/Beltway neoliberal cronies. The party would break. Trump would win a second term, perhaps comfortably.

I mean, if you’re going to a draft a well-known but uncharismatic centrist with no time to compete in the early states, there are certainly other options:

The party’s 2016 nominee, Hillary Clinton, was fielding calls in recent days about whether to get into the race, some close to her said. While it is still unlikely that she will run, some allies have gone so far as to talk about a potential pathway that would bypass Iowa and New Hampshire and focus on making a stand in South Carolina.

Imagine Hillary jumping in and winning South Carolina by bigfooting Biden, thus knocking him out of the race — and then getting crushed on Super Tuesday as the rest of the Democratic electorate resolves that we’re not going to make this mistake again. We’d spend the next year mulling the great what-if: What if Clinton had stayed out and Biden had won SC? Would that have propelled him to the nomination?

Maybe Bloomberg’s “trial balloon” is little more than a way for him to gain a louder megaphone to make the case against Warren and Sanders. No one pays much attention to Mike Bloomberg, financier, when he complains about Democratic radicalism; some attention will necessarily be paid to Mike Bloomberg, Democratic candidate, when he makes the same point, though. But the question in that case is: Is there really no better attack dog against progressivism than a guy worth $50 billion and viewed as a titan of Wall Street? How could there be a worse one? He’ll decide against running in the end, as usual.