There are three tiers in the 2012 presidential field at the moment: former Massachusetts governor Mitt Romney is the first tier, Minnesota Rep. Michele Bachmann comprises the second tier and everyone else running is clumped together in the third tier.

Bachmann, too, has emerged from the pack thanks to strong polling in Iowa and a solid — if not spectacular first fundraising quarter. She is also benefiting from the growing sense that she has “it”, the undefinable quality, which is some combination of charisma, empathy and star power, that distinguishes great candidates from good ones.

As for the rest of the field, it’s a bit of a muddle.

Assuming he runs, Texas Gov. Rick Perry — suggested campaign slogan “ Texas Forever ” — has the best chance to break out of the pack and emerge as a real threat to Romney and Bachmann.

Perry, presumably, can raise enough money to be competitive — Texas is packed with wealthy Republican donors — and southern governors have fared well in Iowa’s caucuses in the past two competitive Republican elections.

Perry is all potential at the moment, however, and the flops of the two most recent highly-touted late entrants — Wes Clark in 2004 and Fred Thompson in 2008 — gives us pause about making too many grand predictions about Perry’s chances.

Both former governors Jon Huntsman (Utah) and Tim Pawlenty (Minn.) have to start showing movement in an early state or run the risk of going the way of Lamar Alexander in 1999 — a candidate with high expectations at the start of the race who never was able to live up to them.

Huntsman edges a spot ahead of Pawlenty on the Line this month simply because he has a bit more time to show movement.

For Pawlenty, his campaign will rest on his performance at the Ames Straw Poll on Aug. 13. Win it — or come in a close second — and he can turn the negative narrative surrounding his campaign around rapidly. Lose and he may not be able to sustain his candidacy.

Huntsman has to start moving in New Hampshire some time soon but since he has only been in the race a month — and is already on his second campaign manager! — he has more time to start his upward ascent in polls.

Beyond those five candidates, there’s virtually no distinction between the others running. All have some relatively small base of support and all will likely win some percentage of votes in the primaries and caucuses to come. But none are seen as viable as the Republican presidential nominee. At least not yet.

The number one ranked candidate is seen as the person with the best chances of carrying the Republican banner in the 2012 general election.

If you have thoughts on our rankings or have you own, let’s hear about it in the comments section below.

To the Line!

10. Newt Gingrich: The former House speaker’s campaign is in all kinds of trouble right now, but his biggest obstacle for the time being is money. Despite building a reputation as someone who could raise big money for all kinds of different ventures, it hasn’t translated to the campaign as Gingrich raised just $2.1 million in the second quarter. What’s worse is that his campaign spent even more than that, and has about $700,000 in debt – including about half a million dollars related to the use of private planes. Not good. (Previous ranking: 9)

9. Ron Paul: There is an outside shot that the Texas congressman could win the Ames Straw Poll. While we think its unlikely, Paul is the only candidate running at Ames who has done it before and, unlike last time, he will have all the money he needs to put his best foot forward. Paul is beloved by a relatively narrow band of the GOP. And he’s never shown any interest in trying to grow beyond that base of loyal supporters. (Previous ranking:10)

8. Rick Santorum: Santorum’s second-quarter fundraising number — $582,000 raised — is not going to make anybody take him more seriously. He is getting good reviews for his debate performances, but he has been eclipsed by the rise of Bachmann, who checks a lot of the same boxes as he does and is a fresher and more interesting face for the party. (Previous ranking: 8)

7. Herman Cain: Cain’s growth in this race has been stunted both by Bachmann and by his own missteps. Put plainly: Cain is proud of the fact that he’s not a politician, but it’s also exceedingly clear that he’s not a politician at times. Between raising his voice to a reporter, offering confusing answers about Muslims, losing staff and burning through all the money he raised in the second quarter, there’s plenty of evidence that he’s not ready for primetime. By the same token, he’s still in third place in Iowa, according to the most recent polls. (Previous ranking: 7)

6. Sarah Palin: All’s quiet on the Palin front, at least for now. After a much-hyped bus tour up the eastern seaboard re-ignited speculation about her presidential plans, the rest of the bus tour got put on (permanent?) hiatus. This has been a pattern with Palin, who seems to disappear and then re-insert herself into the presidential picture every few weeks. What’s clear though: there is no evidence that she’s actually ramping up a presidential campaign, and it’s getting to be about that time. One potential scenario: Palin stays out but offers an early endorsement of Perry. Now THAT would be interesting (Previous ranking: 6)

5. Tim Pawlenty: The former Minnesota governor needs a spark and he needs it soon. Pawlenty is all in for the Ames Straw Poll — running television ads and all but living in the state between now and Aug. 13. While the Pawlenty campaign is doing everything it can to downplay expectations in advance of the straw vote, it’s hard to see how anything other than a first or a close second place finish keeps him in the race. (Anything below that will make fundraising a near impossibility.) With so much riding on Ames, Pawlenty needs to have the best 22 days of his campaign between now and Aug. 13. (Previous ranking: 2)

4. Jon Huntsman: The decision to replace Susie Wiles as campaign manager on Thursday suggests that the former Utah governor wasn’t happy with the first month of his campaign. Huntsman’s is nowhere near where he needs to be in New Hampshire just yet and there appears to be an active debate within his campaign about whether he should start advertising in the Granite State to bump his numbers up. Whether he goes on TV or not, Huntsman needs to start showing progress — and soon. (Previous ranking: 4)

3. Rick Perry: The Texas governor seems to have stolen some of Bachmann’s buzz of late, but will he steal her path to victory too? Perry is looking like Bachmann’s most formidable opponent in Iowa should he get in — which it looks more and more like he will do. For Perry, the field has essentially shaken out too well for him not to run. The question now is whether he has the fire in the belly required and can adjust to federal campaign finance limits. (Previous ranking: 5)

2. Michele Bachmann: The Minnesota Republican Congresswoman’s meteoric rise in the race has been noithing short of remarkable, but there are several things weighing her down. One is plenty of disgruntled former staff. She has gone through lots of staff during her five-plus years in Congress, and not all of them are favorably inclined to her — hence the recent stories about her supposedly debilitating migraine headaches. The second is her family business, which her husband acknowledged will try to help gay men become straight if asked. That may not hurt her in Iowa and may actually make her even more of a hero among social conservatives, but it’s too juicy a story to not be a persistent pain for her campaign. (Previous ranking: 3)

1. Mitt Romney: Romney continues to put distance between himself and the rest of the field thanks to a laser-like message focus on President Obama’s handling of the economy. While some questions have been raised about whether Romney is taking it too slow in the race, it’s hard to argue with his early results. Romney remains something short of a strong frontunner as many donors and activists continue to sit on the sidelines and wait to see who else might get into the race. And, health care, which has dropped out of the news of late, is still a major hurdle to overcome for Romney. But, viewed broadly, he is clearly the class of the Republican field at the moment. (Previous ranking: 1)

Aaron Blake contributed to this report