Sen. Ted Cruz (R-Tex.) speaks to guests at the Iowa Freedom Summit on Jan. 24 in Des Moines. (Photo by Scott Olson/Getty Images)

A prominent Republican consultant — who isn't working for any of the 2016 presidential candidates and who has been right more times than I can count — said something that shocked me when we had lunch recently. He said that Texas Sen. Ted Cruz had roughly the same odds of becoming the Republican presidential nominee as former Florida governor Jeb Bush.

Jaw-dropper, right? After all, the conventional wisdom is that Bush, the son and brother of presidents, is the frontrunner to be the Republican standard-bearer, while Cruz, a conservative's conservative, is a factor, sure, but not someone who could actually win the nomination.

How, I asked this guy, could he say such a thing? He explained it this way.

Think of the Republican primary field as a series of lanes. In this race, there are four of them: Establishment, Tea Party, Social Conservative and Libertarian. The four lanes are not of equal size:  Establishment is the biggest followed by Tea Party, Social Conservative and then Libertarian. (I could be convinced that Libertarian is slightly larger than Social Conservative, but it's close.)

Obviously the fight for the top spot in the Establishment lane is very crowded, with Bush and possibly Wisconsin Gov. Scott Walker leading at the moment. Ditto the Social Conservative lane with former Arkansas Gov. Mike Huckabee, Ben Carson and Rick Santorum all pushing hard there. The Libertarian lane is all Kentucky Sen. Rand Paul's but, as I noted above, it's still not that big.

Which leaves the Tea Party lane, which is both relatively large and entirely Cruz's. While Paul looked as though he might try to fight Cruz for supremacy in that lane at one time, it's clear from his recent moves that the Kentucky senator is trying to become a player in a bunch of lanes, including Social Conservative and Establishment.

So, Cruz is, without question, the dominant figure in the Tea Party lane. What that means — particularly in the early stages of the primary process in places like Iowa, New Hampshire and South Carolina — is that he will likely be able to win, place or show repeatedly, wracking up enough strong-ish performances to keep going even as the Establishment lane and the Social Conservative lane begin to thin out. (Cruz's ability to raise money, which remains a question, is less important for him than it is for other candidates — especially those in the Establishment lane. His people are going to be for him no matter how much — or little — communicating he does with them.)

The trick for Cruz, according to this consultant, is to hang around long enough to not only be the preeminent figure in the Tea Party lane but also in the Social Conservative lane. (Cruz is decidedly conservative on social issues and talks regularly about his faith on the campaign trail.) The complicating figure in that consolidation effort is Huckabee, who is a) likely to run, b) an ordained Southern Baptist minister, and c) likely to be able to stay in the race for an extended period of time because of the number of Southern primaries in the early stages of the primary process.

But, let's assume, for the sake of argument, that Cruz is able to outlast Huckabee (as well as Carson and Santorum). If you combine the Tea Party and the Social Conservative lanes, that's a pretty wide berth for any candidate hoping to be the GOP nominee. Is it as wide as a consolidated Establishment lane behind Bush or Walker or Sen. Marco Rubio (Fla.)? No one knows just yet, but it's probably pretty close.

So, watch Cruz. The combination of his running room as the race's one true tea-party candidate, his debating and oratorical skills and his willingness to always, on every issue, stake out the most conservative position make him a real threat.

The 10 candidates with the best chance of being the Republican candidate in 2016 are ranked below. The No. 1 ranked candidate has the best shot as of today.

10. Indiana Gov. Mike Pence: The newest entry on this list, Pence replaces Rep. Paul Ryan (Wis.) because Ryan said he won’t run. Pence hasn't ruled it out, though he’s likely got to choose between running for president and for reelection in 2016. One recent development: Pence expanded Medicaid in Indiana after negotiating some concessions from the Obama administration — though we’re not sure if this would help or hurt him in 2016.  More on that here. (Previous ranking: N/A)

9. Former Arkansas governor Mike Huckabee: Huckabee is giving every indication he is running. If he does he will be a factor in the race because of his strong following among social conservatives. But, if he can't correct the mistakes of his 2008 campaign — meager fundraising and a skeleton national staff — it's hard to see how he has a real chance at winning. (Previous ranking: 8)

8. Louisiana Gov. Bobby Jindal: Jindal is, as we've mentioned before, the résumé candidate in the GOP field. He’s shown us little besides that, though, apart from occasionally tossing some red meat to the conservative base. The latest example: Not backing down from his comments on so-called no-go zones for non-Muslims in Europe. But we also have to wonder what Jindal has to show for stuff like this. So far, it’s not much. (Previous ranking: 7)

6. (tie) Sen. Ted Cruz (Texas): See above.  Remember that while Cruz is roundly derided by his colleagues — Democrats and Republicans — in the Senate, he may be closer to how the Republican base feels on most issues than anyone else running. (Previous ranking: 9)

6. (tie) Ohio Gov. John Kasich: After lying dormant for a few months after his convincing 2014 reelection victory, Kasich will spend two days next week in South Carolina. That trip will spark some buzz about whether he will run, but Kasich may have waited too long already since Walker, another Midwestern governor from a swing state, is on the rise. (Previous ranking: 6)

5. New Jersey Gov. Chris Christie: Increasingly, it’s looking like Christie missed his window for running for president in 2012. A new Rutgers-Eagleton poll shows his favorable rating in New Jersey has dropped to 37 percent — after topping out at nearly 70 percent. And it’s not just his home state. Polls of likely GOP voters in Iowa and New Jersey show he is the most unliked Republican not named Donald Trump. (Previous ranking: 4)

4. Sen. Rand Paul (Ky.): Speaking of people whose stock is dropping, Paul’s vaccine comments continue to baffle us — especially since he continues to play the victim card. Yes, there is a segment of the GOP that probably likes the idea that Paul is taking on the “liberal media." But there's also a much bigger portion of the party that will look at his vaccine flap and see Ron Paul Version 2.0. A recent poll showed just 11 percent of Republicans harbor any doubts about the measles vaccine — which has erroneously been linked to autism — and just 5 percent are convinced it's not safe. Paul insists he thinks vaccines are safe, which makes it really hard to understand why he saw fit to mention kids getting "profound mental disorders" after receiving vaccines. (Previous ranking: 2)

3. Sen. Marco Rubio (Fla.): Yes, Rubio's path to the nomination is complicated by Bush's all-but-announced candidacy. But, if Republican voters are looking for a fresh face who could, theoretically, expand the party's appeal, then Rubio could be the darkhorse in the race. Add to that profile his natural abilities — rivaled only by Christie in the field — and you have the makings of an intriguing candidacy. (Previous ranking: 5)

2. Wisconsin Gov. Scott Walker: Walker is clearly ascendant right now, thanks in large part to his strong speech at an Iowa confab a few weekends ago. We’ve gone over this in a few different ways now. But as 2012 showed, a boomlet can quickly disappear as scrutiny increases. Walker’s ham-handed handling of an evolution question and his decision not to answer questions in London are not good signs — especially for a guy who seemed to be pretty comfortable in his own skin. (Previous ranking: 3)

1. Former Florida governor Jeb Bush: Bush remains the top dog here, and he got a big break when Mitt Romney opted not to run. Bush probably would have remained No. 1 even if Romney got in, but the 2012 nominee’s exit makes Bush the obvious choice for GOP establishment types to rally around. They might not all join forces — some could go to Walker or even Christie, Rubio or Kasich — but a Romney-less field means more will likely be headed in Bush’s direction. (Previous ranking: 1)