WASHINGTON, D.C. -- The GOP presidential field, already 16 candidates strong and brimming with controversy, features a large number of contenders who are familiar to Republicans nationwide. Donald Trump leads the pack as the best-known candidate, at 92%.

However, the best-known candidates, Trump and Jeb Bush, are not the best-liked. That distinction goes to Marco Rubio and Ben Carson, who enjoy the highest advantage in their net favorable ratings.

These data are based on two weeks of interviewing conducted on Gallup Daily tracking, spanning July 8-21, with a total of 1,028 Republicans and Republican-leaning independents. This was an eventful time on the campaign trail. On July 18, Trump said that longtime GOP senator and 2008 presidential nominee John McCain, a prisoner of war in Vietnam for five years, was not a war hero. Despite nearly universal condemnation of Trump's remarks from other presidential candidates, Trump did not budge from his views.

While Trump is probably the most heavily covered GOP candidate at the moment and is certainly the most well-known, he is hardly running against a cast of anonymous or unknown rivals. Besides Trump, three other candidates are familiar to at least 70% of self-identified Republicans, meaning Republicans know enough about the candidate to give him or her a "favorable" or "unfavorable" rating: Bush (81%), Mike Huckabee (73%) and Chris Christie (72%). Another seven candidates enjoy familiarity ratings above bare-majority levels among self-identified Republicans, but below a supermajority of 70%. These candidates include Rand Paul (68%), Rick Perry (67%), Ted Cruz (66%), Rubio (64%), Rick Santorum (57%), Lindsey Graham (55%), Scott Walker (52%) and Bobby Jindal (51%).

Carson, whom half of Republicans are familiar with, nonetheless enjoys a net favorability -- the difference between a candidate's favorable and unfavorable ratings -- of +40, among the highest of all the candidates, meaning Carson is exceptionally well-liked among the smaller subset of Republicans who know him. Other lesser-known candidates, especially Ohio Gov. John Kasich (35% familiarity), are more recent entrants into the field, so their low name recognition may not be a problem for them just yet.

Growing Number of Candidates Well-Known and Well-Liked

A growing number of candidates are in the "sweet spot" of public opinion, meaning they are comparatively well-known among the GOP base as well as comparatively well-liked. Rubio has a +42 net favorability, slightly better than Carson's, and 64% of Republicans are familiar with him. Huckabee and Perry also occupy this advantageous space -- each is slightly better-known than Rubio but is slightly less well-liked. Finally, these findings are a reminder of the importance of campaigning; the best-known, best-liked Republican candidates also happen to be, in many instances, the ones who have been campaigning the longest. Cruz was the first candidate out of the gate, with Paul and Rubio close behind. Bush, meanwhile, officially announced only recently, but his candidacy was far from a secret, and he was engaging in activities that resembled a campaign well before his announcement.

Several Candidates Well-Liked but Not Well-Known

Three candidates are comparatively well-regarded in the GOP field but are not well-known. Carson, Walker and Jindal all have essentially the same familiarity rating of about 50%, but each man has a higher-than-average net favorable score. Carson, in particular, has one of the highest net favorable scores of all candidates, at +40.

Pataki Struggling by Wide Margin in Familiarity and Favorability

Five candidates occupy the "no-man's land" of below-average name recognition and below-average favorability. By these metrics, no GOP candidate seems as challenged as former New York Gov. George Pataki. Despite running one of the largest states in the country during a trying time that included the 9/11 attacks, Pataki is familiar to about half of Republicans nationwide (49%). Complicating his chances further, Pataki is more disliked (28%) than liked (21%) among Republicans. He is currently the only candidate in the GOP field to receive a negative "net favorable" score, an unenviable feat. Meanwhile, 2012 runner-up Santorum again finds himself beginning a race in a difficult place in terms of recognition (57%) and likability (+19). Former Hewlett-Packard CEO Carly Fiorina is dogged more by low name recognition (39%) than low likability (+23).

For Trump and Christie, Name ID Outpacing Likability

Two candidates known for their "better to be feared than loved" style of interacting, Trump and Christie, find themselves in the unwelcome position of being well-known, but comparatively less well-liked. Trump's name recognition is nearly universal, but his net favorability is below average (+20). Given the state of affairs of his contentious campaign, it is hard to foresee his favorable rating rising by a substantial share. For Christie's part, the two-term governor has about as many Republican admirers (39%) as detractors (33%).

Bottom Line

With one of the largest presidential fields in recent history, the Republicans have a number of well-known candidates from whom to choose when the primary campaign gears up. The group of familiar candidates poses clear challenges for candidates who currently have a much lower national profile. In the long run, both types of candidates, the well-known and the less so, are aiming to promote their likability as an influential factor in determining GOP voters' decisions.

Survey Methods

Results for this Gallup poll are based on telephone interviews conducted July 8-21, 2015, on the Gallup U.S. Daily survey, with a random sample of 2,374 adults, aged 18 and older, living in all 50 U.S. states and the District of Columbia. For results based on the total sample of national adults, the margin of sampling error is ±2 percentage points at the 95% confidence level.

For results based on the total sample of 1,028 U.S. adults who identify or lean with the Republican Party, the margin of sampling error is ±4 percentage points at the 95% confidence level. All reported margins of sampling error include computed design effects for weighting.

Each sample of national adults includes a minimum quota of 50% cellphone respondents and 50% landline respondents, with additional minimum quotas by time zone within region. Landline and cellular telephone numbers are selected using random-digit-dial methods.

Learn more about how Gallup Daily tracking works.