The Democratic nominee to replace former Rep. Gabrielle Giffords (D-Ariz.) has a double-digit lead over the Republican one day out from the special election, a new poll showed.

Democrat Ron BarberRonald (Ron) Sylvester BarberPrinciples and actions mean more than Jeff Flake’s words Giffords to lawmakers avoiding town halls: 'Have some courage' Ten House seats Dems hope Trump will tilt MORE, a former Giffords aide, takes 53 percent to Republican Jesse Kelly's 41 in a survey by Democratic firm Public Policy Polling.

Arizona Democrats have suggested they believe the momentum is on their side, but that most anticipated a much closer race between Barber and Kelly, who came within 2 points of unseating Giffords in 2010.

Barber enjoys a favorable reputation among the slightly GOP-leaning electorate in southern Arizona, with 53 percent viewing him favorably and 41 percent unfavorably. Voters disapprove of Kelly 59-37, the poll showed.

As in many other conservative-leaning states, the Democrat will have to run several points ahead of President Obama in order to win — and Barber is positioned to pull that off as well, according to the poll. Barber's lead comes despite a 44 percent approval rating for Obama among voters in the district, where 50 percent disapprove of the president.

Another element working in Barber's favor is early voting, which is expected to make up the majority of votes cast in Tuesday's special election. Among the 57 percent of voters who said they'd already cast their ballots, Barber had a 21-point lead.

The poll of 1,058 likely voters was conducted June 9-10 using automated telephone interview and had a margin of error of 3 percentage points.