Vice President Biden (PeteMarovich/Bloomberg)
Daniel W. Drezner is a professor of international politics at the Fletcher School of Law and Diplomacy at Tufts University and a regular contributor to PostEverything.

As the first presidential debate for the Democrats airs Tuesday night, there’s a quasi-candidate who will not be taking the stage, not even via hologram. Vice President Biden has been flirting with throwing his hat into the ring, and he hasn’t done it yet. While CNN seemed willing to do just about anything to get Biden onto that stage, it looks like he won’t be showing up.

Let me put my cards on the table: As a political scientist, I really, really hope that this debate marks the end of the mainstream media’s “Biden could be running!” boomlet.

It began with a Maureen Dowd column two and a half months ago and has persisted ever since. And I totally get the media enthusiasm over a Biden candidacy. He’s not boring, as a sitting VP he’s an automatically credible candidate, his possible entry creates all kinds of exciting narratives and dynamics, and he injects some excitement into a nomination race that, compared with the GOP, has been sedate.

But the political scientist in me looks out at the current landscape and notes the following:

1. The only political reason for a Biden candidacy was an imploding Hillary Clinton, and she’s not imploding. Sure, Clinton trails Bernie Sanders in New Hampshire but not nationally, not in Iowa, and not in South Carolina or Nevada either. Furthermore, the poll numbers in recent weeks contradict the narrative of Clinton only trending downward. She has improved her position nationally and in Iowa over the past few weeks, and her favorability numbers have also gone up. Her big money supporters seem concerned about Biden but “are feeling encouraged for the first time in months.” The biggest problem Clinton has faced has been the e-mail scandal, but two GOP own-goals in the last two weeks have, at a minimum, cauterized that wound.

Biden’s peak popularity was a few weeks ago. If his numbers had continued to rise inexorably, I could see him being unable to resist getting into the race. But they’re actually trending downward ever so slightly. The only viable scenario where Biden could come in to secure the nomination has evaporated.

2. The media is beginning to tire of the Biden story. It’s the media that stoked the Biden flame, but after two and a half months of it, they’re starting to grow weary of the non-story. As my colleague Greg Sargent noted five days ago:

Mr. Vice President, enough is enough. The first Democratic presidential debate is in five days. Tell us what you’re going to do already. …

But the game Joe Biden is playing now, in holding back on making his decision and telling us what he plans to do, just has to end, and fast. At best it’s becoming a farcical distraction that is beneath him. At worst it’s becoming a serious waste of our time.

And now the New York Times’ Maggie Haberman and Peter Baker have added to the drumbeat:

Perhaps not since Mario M. Cuomo, then the governor of New York, left a plane bound for New Hampshire idling on a tarmac in 1991 has there been such an extended and late-hour public agonizing by a major political figure over whether to run for president. Mr. Biden initially said he would decide by the end of summer. Now aides are researching filing deadlines to see if he can keep his options open into November.

The danger for Mr. Biden, as his advisers know all too well, is that intrigue can easily turn into fatigue. After 10 weeks of his being egged on by Democrats disenchanted with Mrs. Clinton and by a news media eager for a race to cover, Mr. Biden increasingly faces demands that he make up his mind.

The first rule of Presidential Fight Club is that everyone talks about Presidential Fight Club. But the second rule is: never get compared to Mario Cuomo when it comes to making a decision about running. And since the next news cycle is going to focus on the debate, that’s another cycle where Biden doesn’t play a role. And finally:

3. Biden. Can’t. Win. Remember when Rick Perry entered the 2012 race in August, and it was clearly too late for him to do so? Remember Fred Thompson doing the same thing in 2008? And Wes Clark doing the same thing in 2004? Biden would be entering the race much later than that, and at a much more decided disadvantage. Clinton has already won the invisible primary. The moment Biden were to actually become a candidate would be the moment that Democrats and the media remember all the Biden baggage.

Biden is about as traditional a politician as there is in D.C. He’s not going to run for an office knowing that he cannot win. And he can’t win the Democratic Party nomination. Not now.

In writing all of this, could Biden still enter the race? Sure, anything is possible, particularly this year. But Biden entering the race later this month or in November would be what political scientists would call an “off the equilibrium path” outcome. It would be surprising precisely because everyone knows how it would end. There are simply too many factors that prevent Biden from actually winning the nomination at this point in the race.

So I’m calling it. Rest in peace, Draft Biden movement. You had a good two-month run, but it’s time to close up shop with some dignity.