Rebekah L. Sanders, Julia Shumway, and Daniel González

Ruben Gallego, who organized campaign supporters with the discipline of his Marine Corps training, won the Democratic primary for the 7th Congressional District.

The west-Phoenix district is so blue the former state lawmaker will likely coast to victory in the Nov. 4 general election. Gallego would become the first Iraq War veteran to go to Congress from Arizona.

"I have to fill some very big shoes and that's Ed Pastor," Gallego told 12 News of the congressman, who's retiring after representing the district for 23 years. "I'm going to do my best to represent this state well."

Gallego pledged to fight for immigration reform and increased education funding.

Phoenix Mayor Greg Stanton praised the candidate, whom he endorsed in the last days of the campaign. "Ruben Gallego's going to be a warrior for us just like he was a warrior in Iraq," Stanton said.

Gallego's main rival, former Maricopa County supervisor Mary Rose Wilcox, called to concede the race shortly before 9 p.m. On Twitter, she wished him "the best of luck."

Wilcox told supporters at her restaurant that she would continue to push for immigration reform.

"We're still going to fight. We're probably going to get arrested together for it," she said. "Sí, se puede."

The race was a generational battle between Gallego, 34, and Wilcox, 64. Their attacks centered on gun control, race and personal finances in the Phoenix and West Valley district packed with minority voters.

Less experienced competitors Randy Camacho and the Rev. Jarrett Maupin posedlittle threat. Independent Jose Peñalosa and Libertarian Joe Cobb will compete with the Democratic nominee in the general election.

Pastor, the state's first Latino congressman, made his surprise retirement announcement in February, setting off a scramble for the seat.

Gallego had his eye on the higher office during his two legislative terms. As soon as news of Pastor's retirement broke, he announced his candidacy and launched a campaign driven by technology and strategic door-to-door canvassing.

He emphasized his upbringing in poverty by an immigrant single mother, his education at Harvard University and his military experience. Gallego promised to be an advocate for liberal policies in Washington and locked up union support. He criticized Wilcox for failing to pay taxes and benefiting from a land deal with Arizona Public Service Co.

Wilcox, who received Pastor's endorsement, put up an intense fight, drawing on her network of supporters built over three decades in public office and battles with Maricopa County Sheriff Joe Arpaio. She deployed a traditional door-knocking operation and garnered endorsements from national Hispanic leaders.

She highlighted her work with the community and hammered Gallego for voting for looser gun restrictions and earning a B+ rating from the National Rifle Association.

Zany antics punctuated the race.

A former Republican who legally changed his name to Cesar Chavez and became a Democrat was kicked off the ballot. Wilcox's attempt to keep Gallego off the ballot blew up because of her campaign's incomplete research.

Maupin, a pastor, touted an endorsement from a strip club, saying that Jesus had ministered to prostitutes.

The 7th District has one of the lowest rates of voter turnout in the country — 14 percent in the 2012 primary. The candidates pledged to mobilize supporters in the fall to drive up participation and help other Democrats, including gubernatorial hopeful Fred DuVal.