Hillary Clinton, former U.S. secretary of state, smiles during a news conference at the United Nations (UN) in New York, U.S., on Tuesday, March 10, 2015. Photographer: Victor J. Blue/Bloomberg

Democrats are in a bit of a panic these days as Hillary Clinton's handling of her use of a private e-mail address during her time at the State Department has raised questions about her readiness for the presidential race. At least four times in the last 48 hours, I have fielded questions from people who aren't in the professional political class but consider themselves Democrats, all of which amount to this: Isn't someone going to run against her in the primary now?

And, the answer I keep giving is: Almost certainly not. There are a few reasons that explain that belief.

1. The Democratic bench stinks.  As Dan Balz noted in his terrific analysis Wednesday, "the absence of a strong Democratic bench has never been more apparent." Let's take a look at the candidates who are actually running or who we expect to run. Martin O'Malley, the former Maryland governor, is potentially appealing for his charisma and liberal record, but the fact that his chosen successor lost a governor's race last November in a very Democratic state -- largely due to negative opinions about O'Malley -- has taken some shine off of him. Both former senator Jim Webb (D-Va.) and current Sen. Bernie Sanders (I-Vt.) are running causes, not campaigns. Both have a set of pet issues that they want to broadcast to a larger audience and see running for president as a way to do that. Neither has any realistic expectation of winning -- or coming close. Vice President Biden, at 72 as of today, would be the oldest person ever elected president -- and it's not clear he could win (or even come close to winning), given his penchant for saying inappropriate things. New York Gov. Andrew Cuomo has watched his poll numbers slide over the past few years. New York Sen. Kirsten Gillibrand, who took Clinton's seat in the Senate and could be potentially appealing as a national candidate, would never challenge Hillary in a primary. Former Massachusetts governor Deval Patrick sounds interested in running for president but not in this election. Minnesota Sen. Amy Klobuchar isn't showing any signs of moving toward a bid.

2. Elizabeth Warren isn't running. The one person who could pose a Barack Obama-like challenge to Clinton is the Massachusetts senator. As a populist, anti-Wall Street crusader, Warren is far closer to the beating heart of the Democratic Party than Clinton is or ever will be. And, unlike people such as Sanders, Webb and O'Malley, Warren has demonstrated a capacity to raise lots of money from a national donor base. (She brought in more than $40 million for her 2012 Senate victory.) But Warren, according to every public statement she has made and every scrap of private conversation I have been able to pick up from my reporting, just isn't running under virtually any circumstance. If Clinton got out, yes, I think Warren would be forced to reconsider her lack of interest. Short of that, I can't see it. And, in a related but important note: There isn't an obvious and credible alternative to Warren on the liberal left. Sure, Sanders will carry a similar message, but his expected inability to raise serious money means that no one will hear it. And, after Warren and Sanders, the leading liberal voice who is positioned to run for national office is.....? Exactly.

3. It's too late. What, you say? Too late? It's only March 2015! Sure, no one is going to cast a vote for more than nine months. But running for president is, at least, a two-year endeavor. If someone wanted to mount a serious challenge to Clinton, that person should have already started to mount a serious challenge to Clinton. Remember that Barack Obama was already an announced presidential candidate by this time in 2007.  He got in that early because he and his campaign team understood that the task of raising the money and building the sort of organizations in early states (and beyond) necessary to topple a figure as formidable as Clinton was going to take a long time. Clinton is, inarguably, more formidable today than she was back in 2007. And there is no Barack Obama figure already running.

I've taken to thinking about Democrats' relationship with the inevitability of the Clinton candidacy and primary victory like waiting in a long line. Lots and lots of Democrats have spent the last six months getting in the Hillary line, shuffling forward every few days as she nears the now-inevitable announcement of her candidacy. The line might have started relatively short a year or 18 months ago. But now it's huge -- and lots of Democrats have been waiting in it for a very long time. They have too much invested in the line-waiting to jump out of line just because it starts to rain a little bit on them. Hell, I'm not even sure a full downpour would drive them out of the line. (This metaphor is heavily influenced by my recent trip to Disneyworld with my two 6-and-under children.)

This e-mail controversy isn't a political downpour (or close) yet. And even if it turns into one, don't expect an abandonment of Clinton. The party has been waiting in her line too long to realistically walk away now.