As big as Congressional District 1 is, perhaps the candidates will breathe a sigh of relief when they hear there are 5,461 fewer voters for them to woo.

The Arizona Secretary of State's Office released a new report on voter registration numbers Monday, and it shows a small overall decline in registered voters statewide since the last report in June. That's also true in the huge new congressional district that runs from Cochise County's northern border to near Colorado City on the Utah line.

County election officials' efforts to clean up their voter rolls likely explain the declines, said Matt Roberts, spokesman for the secretary of state's office. Those efforts include actions such as re-sending mail to addresses where earlier mail to voters was returned undeliverable, he said.

In CD1, a swing district with national significance, the party balance remained essentially unchanged from the June report.

As of Aug. 14, there are 139,568 registered Democrats, down by 2,590 but still equivalent to about 39 percent of total registered voters in the district.

The report showed 111,535 Republican registered voters, down by 1,001 but still equivalent to about 31 percent of all voters.

And there were 107,178 "other," or independent voters, which was down by 1,847 and equals about 30 percent of all voters.

Voters registered with the Green, Libertarian and Americans Elect parties number less than 1 percent of the total in the district.

The counties with the most registered voters in the district are Pinal County, with 84,442, Coconino County, with 64,866, and Navajo County, with 58,628.

Pima County voters in the district, who live on the far northwest side of the Tucson area, are the fourth largest group, with 55,214 registered. Of those, Republicans represent 43 percent, independents are 29 percent and Democrats make up 26 percent.

In the Aug. 28 Republican primary, front runner Jonathan Paton, of the Tucson area, is facing Gaither Martin and Patrick Gatti. In the Democratic primary on the same day, one-time congresswoman Ann Kirkpatrick is running against Wenona Benally Baldenegro.