A new internal poll shows Gabrielle Giffords' handpicked successor easily defeating both his Democratic primary opponent and his Republican rival as he tries to win a full term in office.

The poll, released Wednesday by Rep. Ron Barber (D-Ariz.), shows the newly elected congressman with a commanding 77 percent to 13 percent lead over state Rep. Matt Heinz in the Aug. 28 Democratic primary for the full term. The poll also shows Barber holding a 53 percent to 40 percent lead over Republican Martha McSally in the November election. The poll was conducted late last month by Greenberg Quinlan Rosner.

Barber, a former Giffords aide, defeated Republican Jesse Kelly in a June special election to complete the final six months of the former congresswoman's term. Giffords resigned in January to focus on her recovery from gunshot injuries sustained in a January 2011 assassination attempt. Barber was shot twice in the shooting spree in front of a Tucson supermarket. Barber, Heinz and McSally are currently competing for a full term in a newly drawn southern Arizona district, which is more politically competitive than the one Barber defeated Kelly in.

The poll numbers show Barber with an 81-percent favorability rating since taking office, outperforming President Barack Obama by 12 percentage points in the district's general election matchup. According to the polling memo, Barber's lead narrows to 11 percentage points over McSally after details are given about McSally's Air Force career.

Heinz, an openly gay doctor and two-term state legislator, was the first candidate to enter the race following Giffords' resignation. He opted out of the special election following Barber's entry, but decided to stay in the race for the full term after Barber decided to run in that election as well. Heinz backed Barber in the special election, while running against him for the full term.