(Elise Amendola/AP)

Hillary Clinton is going to run for president. Jeb Bush is going to run for president. Rand Paul is going to run for president. At least, if you went up to a bookie in Vegas and asked the odds, you wouldn't make much profit in predicting that any of them would be on the ballot.

Perhaps, then, you've wondered: Why don't they just end the pretense and admit it — just say, "I am running for president" and be done with it? Two reasons. First, there are distinct legal and practical reasons not to do so. And second, many actually haven't decided whether to run.

"I have learned — somewhat to my surprise — that when people say that they are considering running, it is often good to take them at their word," Republican consultant Stuart Stevens said when reached by phone. "I don't think you should assume that that is not what they really intend, that it's some sort of charade."

Stevens has worked with a number of presidential campaigns, from George W. Bush to Mitt Romney, and he pointed out that running for president is a unique thing in politics. Most potential candidates are undergoing a level of scrutiny that they've never experienced — scrutiny for them, for their staff and for their families. "Society is moving in a direction where it is harder and harder for family members to remain out of the fray," Stevens said, citing social media tools and omnipresent cameras. For a candidate, that's an important consideration — and one that's hard to suss out until you dip your toe in the water.

And the other point: From a legal standpoint, there's no real need to declare an actual candidacy. The "dip your toe in the water" analogy is precisely the one used by the Federal Election Commission in a document outlining how to prepare for federal office — including a bid for the presidency. We spoke with the executive director of the Center for Responsive Politics, Sheila Krumholz, who walked through the FEC's requirements.

"It's a period that allows [candidates] the comfort of spending time out of the spotlight to gather information they need before making this important decision," Krumholz explained. That includes raising money for things like polling, staffing, research and travel without having to report who made the contribution. At least not until they announce their candidacy — if they do. If the maybe-candidate chooses to run, any contributions need to be reported.

(What counts as an announcement? Filing the necessary paperwork with the FEC (this paperwork) marks that point. So does making a public announcement, at which point it becomes "official enough," in Krumholz's words. "You can't make an announcement and then tell the FEC, 'No, no, I'm not a candidate.' ")

"There's a huge legal advantage now, post-Citizens United in particular," Krumholz said, referring to the 2010 Supreme Court decision on campaign fundraising. That decision has shifted the center of gravity for campaign spending away from candidates for office and to the political action committees of outside groups — often what are referred to as "super PACs." Candidates for office can't coordinate with those organizations, can't plot strategy and fundraising targets and messaging. But I-don't-know-if-I-will-be-a-candidate candidates still can.

"From a very pragmatic standpoint, candidates would be viewed as foolish if they don't take advantage of the opportunity to set up a super PAC to be able to coordinate during this period," Krumholz said. Which is what Bush has already done. Clinton, too, has PACs acting on her behalf, including the well-covered Ready For Hillary. Up until the point at which Bush or Clinton declares, the not-yet-candidates and any outside groups can put together intricate plans for the next two years, and it's all perfectly legal.

(Krumholz: "This is just the best example of the old adage: The outrage isn't what's illegal, it's what's legal.")

In fact, not-yet-candidates could run all of the aspects of a campaign without yet being a candidate for office — and all without having to show their cards to their opponents. "The legal structure allows you to do what you need to do," Stevens said. "Under this framework, you can begin the work of organizing." The not-yet-candidates themselves can hire staff, do polls, test the strengths of possible opponents — all out of their own bank accounts, if they want. They can ask external PACs to do the same, or even, say, run ads bolstering the not-yet-candidate (or bashing opponents).

The impatience felt by those watching from the outside, including the hyperactive media to which this writer belongs, is not an asset to those who actually might run. "I think the greatest understated political virtue is patience," Stevens said. "It's the classic cliché: You have to let the game come to you."