The Washington PostDemocracy Dies in Darkness

The one big reason all of Hillary Clinton’s top challengers are unlikely to run

The Hill is out with a list of the top five Democrats who could challenge Hillary Clinton from the left in the 2016 presidential race.

This isn't breaking any new ground, and it's largely the usual suspects. But as the debate over potential challengers to her in 2016 heats up in the months ahead (we're just two and a half months from the start of the 2016 primary campaign) we thought it would be worth looking at why any and all of these folks would not run.

And indeed, their motivations for not running appear, in many cases, to be much more convincing than their arguments for running.

Here are the five:

1. Sen. Elizabeth Warren (D-Mass.) -- praise for Clinton

Warren has said ad nauseam that she is "not running" for president in 2016, a statement that is notably in the present tense. But when it comes to challenging Clinton -- something the New Republic gave some big treatment last year -- we think the present tense applies to the future.

Warren has said repeatedly that Clinton is "terrific" and even praised Clinton in her book for pushing her husband, who was then president, to veto a 1998 bankruptcy reform bill that was supported by the financial industry.

The crux of the Warren-vs.-Clinton argument is that Clinton is too closely aligned with big finance and moneyed interests and not liberal enough. Given Warren's repeated praise for Clinton -- including on finance issues -- that could be a hard case for her to prosecute.

2. Vice President Biden -- presidentiality (if that's actually a word)

Biden has been angling toward a 2016 campaign harder than basically any other Demcorat, up to and including Clinton. And the idea that he will simply stand down for her seems far-fetched -- especially who you consider the 71-year-old two-time presidential hopeful faces perhaps his last chance to run.

But there is plenty of reason for him not to do just that, and the biggest reason is viability.

While others on this list are largely unknown, Biden doesn't have that problem. His problem is that people don't see him as being particularly presidential. A Quinnipiac poll in November showed 51 percent of Democrats and 73 percent of independents say they don't think Biden would make a good president.

When a majority of your own party says that, you've probably got a pretty low ceiling.

3. Maryland Gov. Martin O'Malley (D) -- money

The former mayor of Baltimore seems like one of the more likely big-name Clinton challengers, but even for him, it's a tough choice. Back in May, Politico reported that O'Malley had reached out to Clinton to talk 2016. It also reported that some think O'Malley will run regardless of what Clinton does. That was met with a pretty vigorous denial.

“Anyone who left the meeting with that impression is mistaken,” O'Malley spokeswoman Elisabeth Smith said in a statement. “The governor hasn’t made any decisions about his next steps and certainly did not voice any that day.”

This, of course, is not the same as O'Malley's team ruling out a run against Clinton. But it does suggest that they are being deferential for now. O'Malley himself said recently that "[I] certainly cherish my relationship and working relationship not only with Secretary Clinton and former President Bill Clinton, but also with President Obama."

The big challenges for O'Malley would be fundraising -- given that he's another establishment Democratic politician who would be aiming for the same donors as Clinton -- and viability, with polls showing he's basically a complete unknown on the national stage. (Like, only 16 percent of people know about him, unknown.) But the two work hand-in-hand. You need money to get name ID and viability, and that first step could prove very tough for O'Malley with Clinton in the race.

O'Malley is also only 51 years old. That's a baby by political standards. In other words: He's got lots of time to build a career without making enemies of the first family of Democratic politics.

4. Sen. Bernie Sanders (I-Vt.) -- the s-word

Again, viability is the biggest barrier -- but for different reasons. Sanders, an independent who caucuses with Democrats but has also identified as a "socialist," would quite simply have basically no chance at the Democratic presidential nomination.

It's also pretty clear that a Sanders candidacy would be intended not to win but rather to guide the debate in a more populist (socialist?) direction. So the same calculus doesn't necessarily apply here.

A Sanders run would be predicated on him being able to get enough support to actually be a factor. And the first step in that process is getting liberal groups interested -- something that, as Real Clear Politics writes, isn't happening on the same scale as it is with someone like Warren. Put plainly, we're not quite sure these groups would like to support the socialist in the 2016 race.

Sanders is a well-regarded, longtime officeholder in Vermont. Does he want to run for president if it had a strong likelihood of turning into an embarrassing venture?

5. Sen. Russ Feingold (D-Wis.) -- preparation

This is certainly the most obscure potential candidate mentioned by The Hill. While some are talking about a potential repeat Senate bid for Feingold in 2016, few are talking about him in terms of a presidential campaign.

But Feingold also makes a lot of sense. After all, he has been fighting against government surveillance for years (including the Patriot Act and the NSA), he was an early supporter of same-sex marriage and a strong opponent of the Iraq war, and he has the kind of maverick streak that a Clinton challenger would need.

But Feingold's biggest obstacle is preparation. He has been almost completely absent from politics and the national dialogue since his 2010 loss. Part of this is because he has spent the last year as a special envoy to Africa for the State Department. But even before that, he didn't make much noise.

If Feingold were interested in running for president, it might be time to dip his toe in the water.