PRINCETON, NJ -- Herman Cain and Rick Perry continue to generate strongly favorable impressions among Republicans familiar with them. Meanwhile, those familiar with Mitt Romney, Michele Bachmann, and Ron Paul express less intensely positive opinions of those candidates now than at any point this year. The result is a clear separation of 12 percentage points between the top and middle tiers of Republican presidential candidates in Gallup's Positive Intensity Score from Aug. 15-28 Gallup Daily tracking. The average Positive Intensity Scores show much smaller gaps between the current top- and middle-tier candidates.

Two potential candidates included in the measurement, Sarah Palin and Rudy Giuliani, fall between the middle and top tiers, with current scores of 16 and 17, respectively.

Of all the candidates Gallup tracks, Jon Huntsman has the lowest score, 1. That is also his personal low, and he is one of four candidates, along with Romney, Bachmann, and Paul, to have a personal low in the current data. Newt Gingrich, still mired in the lower tier of candidates with Huntsman and Paul, has shown some improvement in his score in recent weeks, now 7 after descending to 1 at the end of July.

Perry, Romney, Paul, and Bachmann rank as the top four candidates in Gallup's latest GOP nomination preference poll, conducted Aug. 17-21. However, these four candidates' positive intensity trends have diverged in recent weeks, with Perry holding steady or improving but Romney, Bachmann, and Paul generally declining. This is the case even after Bachmann and Paul had the strongest performances in the recent Iowa Straw Poll, though the event was perhaps overshadowed by Perry's long-rumored official entry into the race that same weekend.

Perry has maintained a strongly positive image as he has become much better known among Republicans nationwide. Three weeks ago, 54% of Republicans recognized his name; now, 75% do. That has raised his recognition to an above-average level for the first time.

Perry is now one of five official candidates, along with Romney, Bachmann, Gingrich, and Paul, who is known by at least three-quarters of Republicans. Non-candidates Palin (97%) and Giuliani (91%) remain slightly better known than the announced field of candidates. Cain, Huntsman, and Rick Santorum continue to lag in familiarity.

Lack of familiarity appears to be holding Cain back. Despite strongly favorable reviews among those who know him, Cain registers minimal support in nomination preference polls. In Gallup's latest update, 4% of Republicans and Republican leaners say they are most likely to support Cain for the party's 2012 nomination.

Perry's continuing rise in recognition would seem to solidify his status as the current candidate to beat -- high in both recognition and positive intensity. Huntsman appears to be in the weakest position now, with low recognition and low positive intensity.

Implications

Perry's image remains positive among Republicans familiar with him, even as that group has rapidly expanded in recent weeks from slightly over half to three-quarters of all Republicans. Many other GOP presidential candidates who have shown gains in recognition this year, including Bachmann, Huntsman, and former candidate Tim Pawlenty, saw their Positive Intensity Scores decline as they became better known.

Now, Perry enjoys some separation between himself and his most likely challengers in both positive intensity and support for the nomination (given his 12-point lead over Romney in the latest update), marking him as the clear front-runner at this point in the campaign.

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