Rep. David Schweikert is pulling away from Rep. Ben Quayle in Arizona’s 6th district Republican primary, state and national sources have concluded.

With Arizona voters eligible to begin mailing in their primary ballots last Thursday, knowledgeable observers say Schweikert has more local support and a better ground game. A recent Schweikert internal poll bolstered that narrative, as has his campaign’s aggressive strategy and the perception that Quayle was elected to Congress in 2010 on the name identification coattails of his father, former Vice President Dan Quayle.

“Everything is going according to how we planned to tell our story,” Schweikert told Roll Call.

Schweikert has been a player in Arizona politics for more than 20 years. He has served in government at the county and state levels, over time developing solid recognition among voters and a loyal following among Grand Canyon State political operatives.

According to Schweikert’s internal poll conducted in mid-July, the candidate led his fellow freshman Congressman by 16 points. The survey was conducted by Adam Geller of National Research Inc.

The Quayle campaign has questioned its credibility and attempted to cast doubt on its findings.

“The polls he has been peddling are quite inaccurate, but people believe them when they hear them,” Quayle spokesman Jay Heiler said. “That’s why you are hearing what you are hearing.

“We have polled ahead and the trend lines are good,” he added.

However, the Quayle camp has declined to release its own internal polling or offer other data to counter Schweikert’s claims.

Schweikert’s general consultant, Chris Baker, firmly stands by the poll and its methodology. Additionally, state and national operatives say the Schweikert lead feels right.

One Arizona Republican who appears particularly confident in the predictive quality of Schweikert’s internal polling is Schweikert himself. In an interview, he projected a sunny outlook and cited the survey as a primary source of his optimism about his chances of defeating Quayle in the Aug. 28 primary.

Still, Quayle insists he remains competitive.

“Two-thirds of the district is my current district,” he said. “That gives me a nice little advantage there.”

Possibly helping Quayle’s cause are his proven fundraising skills and high-profile endorsements, including enthusiastic support from Senate Minority Whip Jon Kyl (R-Ariz.), who carries enormous weight with conservatives in the state.

Former Secretary of State Condoleezza Rice has also endorsed Quayle, and Sen. John McCain (R-Ariz.) confirmed that he intends to endorse Quayle “fairly soon.”

“There may well be others,” Heiler said about future top-tier endorsements for Quayle.

Sources in the Schweikert camp downplayed Quayle’s endorsements and fundraising, contending it is a result of his family connections.

Much like Quayle’s 2010 race, his last name comes up in nearly every conversation about the race.

“It’s a double-edged sword,” Quayle acknowledged. “Obviously, the people I’ve met over the course of many years have been able to help and give guidance and give support.”

“But then the other side of it,” he continued, “you have a lot of attention and a lot of arrows getting slung at you, so you have to prove yourself that much more.”

Within the House Republican Conference, Quayle has earned the reputation of a quiet workhorse who keeps his head down. That popularity was reflected when at least six of his fellow Members donated to his campaign in the last report.

But at home, the Schweikert campaign and others in the state have made a concerted effort to portray him as a playboy carpetbagger.

In redistricting, Quayle was just barely drawn out of the 6th district — by about half a block — and has since moved fully into the seat’s boundaries. Early on, Schweikert, too, was carved out but was drawn back in prior to the map’s finalization. There is anger among some Republicans that Quayle did not run in the tossup 9th district, although most unaffiliated political observers concede he got a raw deal in redistricting.

On Capitol Hill, there has been no overt evidence that House GOP leadership is playing favorites in this Member-vs.-Member contest.

Arizona’s Republican House delegation has been equally reluctant to endorse. All but Rep. Trent Franks have primaries of their own. Rep. Paul Gosar has a primary challenge, and Rep. Jeff Flake is in a tougher-than-expected Senate primary with real estate investor Wil Cardon. Amid all of the contentious primaries, strategists say there is no political upside to endorsing in other primaries.

“Everyone’s just sort of mono-focused on their own lives,” Schweikert said.

Gosar, who came to Congress in the 2010 wave with Schweikert and Quayle, offered another reason he has opted not to endorse.

“I’m going to lose a friend,” he said.

When it comes to Quayle and Schweikert’s friendship, both men say they have been friendly but were not the closest of friends prior to this race. The campaign rhetoric has been hot. A Schweikert PAC TV ad personally attacked Quayle, and Quayle’s team questioned the honesty of the Schweikert team on a litany of issues.

Still, the race has not been as nasty as many expected. Even though it has picked up in recent weeks, both Congressmen have avoided throwing around personally negative rhetoric about the other.

Quayle described their relationship as “cordial.”

“We’ve had snippets of the conversation that we understand this is the job,”  Schweikert said. “Being competitive is part of the process.”

Correction: Aug. 9, 2012

An earlier version of this article contained a subheadline with incorrect information about early mail-in ballot counts.