Ready for Joe?

Vice President Biden has made sure to keep the door wedged open for a possible 2016 run, but it looks less likely by the day that he will walk through it.

The dynamic has nothing to do with any diminished appetite on Biden’s part for the top job — and a lot more to do with one other contender.

Hillary ClintonHillary Rodham ClintonThird-party candidate McMullin: We can win Idaho and Wyoming Clinton, Kaine raise over 0M in October Local leaders turning the heat up on Citizens United MORE appears increasingly certain to run in 2016. Many observers, even those sympathetic to Biden, fear that a race against the former secretary of State would be fruitless at best and humiliating at worst for the famously-proud veep.

Biden, they note, has already run twice for the White House, in 1988 and 2008. And they see precious little evidence that the third time would be the charm, if Clinton is also a candidate.

"It's hard for any Democrat to raise money and generate excitement until Secretary Clinton makes a decision," said Democratic strategist Jamal Simmons. 

With former Florida Gov. Jeb Bush (R) announcing this week that he is "actively exploring" a presidential campaign, Democrats might feel even more eager than before to rally behind a single candidate — and there’s no real doubt about who that candidate would be.

"I think with Jeb Bush running, Democrats are going to want to settle the field on the early side," Simmons said. 

Other political observers and strategists say the vice president’s advisers would be wise not to encourage a Biden run against Clinton. 

“He could position, theoretically, himself to the left of Hillary, as an earlier supporter of gay marriage,” said Martin Sweet, a lecturer in political science at Northwestern University. “But it is hard to imagine he can go far with donors ... or present himself with enough gravitas for the job.”

One top Democratic strategist agreed. 

"I think he's smart enough to realize he can't win, were [Clinton] to get in the race," the strategist said. "I haven't talked to very many Biden advisers who think he's going to run for president. They've been going through the motions but no one thinks he's seriously running." 

A poll this week from Monmouth University indicated that few Democrats would support Biden in a primary race.

The vice president received a mere 2 percent when respondents were asked about their preferred candidate in the 2016 primary. 

Clinton ranked the highest among Democratic contenders, at 48 percent. 

The former secretary of State is in the main target for Republicans, too — a backhanded testament to her dominance among Democrats.

“We're doing our due diligence on all the potential candidates for 2016 but clearly our prime focus is Clinton,” said Tim Miller, the executive director of the Republican super-PAC America Rising. “Biden is in the mix with all the others.” 

Democratic super-PACs such as Correct the Record haven’t needed to defend Biden in recent months because he hasn’t been the subject of right-wing attacks.

Even so, Biden — who has visited Iowa and New Hampshire, two essential stops on the primary circuit — has done nothing to definitively rule out a third run for the presidency. In fact, he’s done quite the opposite.

"I'd tell you, I honest to God haven't made up my mind," Biden said at a Politico event earlier this month, when asked if he would enter the presidential race. "I don't see any urgency in making that decision, quite frankly."

But at the same time, the vice president expressed confidence that he would be well-suited to run, if he were to decide to go for it. 

"I'm confident I would be in a position to be able to be competitive, to be able to run a race, to be funded, et cetera," he said, adding that he would announce a decision by the end of spring 2015.

Biden has made it known to his allies that he wants to be actively involved in the dialogue around the 2016 election.

Those allies also note that the best way he can position himself is to do a top-rate job as vice president, marshaling support for President Obama’s policies. 

Biden has proven to be an asset in negotiating with lawmakers on Capitol Hill over the course of the administration, his allies point out. And he has also been helpful on the campaign trail, particularly with candidates who didn’t want Obama appearing at their side. 

"He's done a great job as VP and he'd be a great president but the timing just isn't right," said one former aide to Clinton who served on her 2008 presidential campaign. 

All of this assumes Clinton will run, of course. If she doesn’t, Biden could very well be installed as the front-runner after all.

“If that’s the case, all bets are off,” said the Democratic strategist. “It will be a whole different ball game. And that’s why he’s doing what he’s doing and keeping his options open, just in case Clinton decides not to run.”