Jeb Bush. Maybe running for president.  (M. Spencer Green/AP)

Jeb Bush is more likely than not to run for president in 2016, according to a somewhat garbled quote over the weekend from his son George P. Bush, who is running for Texas land commissioner this fall.  But just because Bush is — or at least might be — running doesn't mean he will win. In fact, even calling Jeb the frontrunner is a drastic overstatement.

"The 2016 field is wide open for business [and] while Governor Bush will be a formidable competitor, he will not clear the field nor have an insurmountable lead," said Dave Carney, a New Hampshire Republican consultant who served as a senior adviser to Rick Perry's 2012 campaign. "He will need to earn it much like his father had to in 1988.  One delegate at a time."

First, let's get straight where Jeb actually is on the race. "Governor Bush has not yet made a decision on whether or not he will run in 2016," said Bush spokeswoman Kristy Campbell in a statement Monday. "He will thoughtfully consider it following the mid-term elections, and make a decision late this year or in the early part of next year." (Make sure to read Peter Baker on the push/pull within the Bush family about Jeb's decision-making process.)

Whether or not he runs — and I'll take his son's word for it that he is leaning toward doing it — there are, at least, four reasons to think that Jeb is not the sort of inevitable nominee that Hillary Clinton is on the Democratic side in 2016.

1. Polling.  This is the most obvious way to debunk the idea that the nomination would be Bush's for the asking. In a field with Mitt Romney, Bush would place second — 10 points behind the 2008 and 2012 candidate — in a recent Washington Post-ABC News poll on the 2016 GOP field.  Take Romney out — since he's almost certainly not running — and Jeb does place first with 15 percent. But Kentucky Sen. Rand Paul takes 12 percent and former Arkansas governor Mike Huckabee is at 11 percent — not to mention a slew of other potential candidates in the high single digits.  So yes, Jeb is the "leader" in that poll, but some large chunk of that support, at least at this point in the race, is dependent on the fact that people know his name.

2. Common Core + immigration reform. Bush is on the wrong side — or at least, on the side opposite the party base — on both of these issues. On Common Core, a series of nationalized education standards, conservatives — including people like Louisiana Gov. Bobby Jindal who will likely run for president in 2016 — have condemned it as a classic case of the federal government thinking it knows best. Bush, on the other hand, has been vocally supportive of Common Core — insisting that while it is not a perfect system, it is necessary to ensure American children can compete against children from around the world. In an interview with conservative blogger Jennifer Rubin last month, Bush seemed to be a bit less confrontational with conservatives who disagree with him on the issue, however. "The principal reason [for the fight] has been the president," Bush said. "There is no trust he will faithfully enforce the law.”

Bush has also been a vocal proponent of the need for comprehensive immigration reform, a position that much of the base views as so-called "amnesty." Bush drew huge national headlines — and lots of conservative scorn — in April when he said that many people who come to the U.S. illegally do so to make a better life for their families, a move he described as an "act of love."

One apostasy might be forgivable in the eyes of the Republican base. But two? "He is too moderate for the Republican base," conservative commentator (and presidential candidate) Pat Buchanan concluded last month.

3. Tone.  It's not only — per point No. 2 above — that Jeb is out of step with the Republican base (and many of the people he would run against) on two big issues. It's his overall tone and approach to issues and politics that will hurt him, said one senior Republican consultant who has worked at the presidential level in the past but is not aligned with any candidate for 2016.  "I think his problem isn’t so much specific issues, it’s his approach to how he discusses them," said the source. "It shows how out of touch he is with the grass roots.  For example, he is not going to be alone in his immigration reform position, most potential candidates support some type of reform.  But how he has addressed the issue so far is likely to be harmful to his efforts, especially if he continues that kind of approach." Bush is not someone likely to kowtow to the base ala Mitt Romney and "self deportation" in 2012. He is someone who knows what he believes and is convinced that in most instances he is right — and that politicians make a major mistake when they let a relatively small segment of the electorate dictate their issue positions.  That is what could make him a very good general election candidate and, potentially, a bad primary one.

4. The dynasty thing. Yes, I realize the irony of including this point in a piece that accepts the idea of Hillary Clinton as the default Democratic nominee. But unlike Clinton, Bush would face real and serious opposition for the nomination if he ran. And that means that the idea that he is part of the past and his opponents are part of the future could be potentially damaging to his chances. "The sense I get from just ordinary folks is, 'enough with the Bushes,' "  said one Republican consultant unaffiliated in the presidential contest. "Hell, even Barbara Bush herself said that!" If Jeb runs, he will need to come up with a smart response to the attack that by nominating him Republicans would forfeit one of their best hits on Hillary Clinton — that she is simply old news.

All of the above is not to say that Jeb Bush wouldn't be a major player for the Republican nomination if he ran. He absolutely would be. And every candidate — Republican and Democrat — has hurdles they need to overcome if they want to win. What is clear, however, is that Bush would neither clear the Republican field nor walk to the nomination if he decides to run. Knowing that, will he decide that the race is worth it or not?