One man's earmark is another man's investment.

Republican U.S. Senate candidate Jeff Flake holds up his decade-long battle against earmarks - which led to both the House implementing a policies to stop the practice - as his signature achievement in Congress.

He wants to make sure Congress doesn't backtrack to an era when members of lawmakers regularly directed funds to be spent on specific projects of their choosing.

"Earmarks became a circumvention of the process that really sullied the whole Congress," said Flake, who has served six terms in Congress representing metro Phoenix.

But his opponent in the U.S. Senate race, Democrat Richard Carmona, has a different perspective. Carmona said the word "earmark" has become a divisive term with a negative connotation, but that as senator he would be the state's chief advocate to bring tax dollars back home to help make Arizona more attractive for potential employers looking to open offices or factories.

"That's smart investment. It's not earmark," said Carmona, the former U.S. Surgeon General making his first run for public office.

Carmona and Flake sparred over the issue during a recent meeting with the Arizona Daily Star editorial board.

Carmona blamed members of Congress who abused the practice for tainting earmarks. But, he said that shouldn't prevent senators from tapping into federal money to help the state improve roads, schools and infrastructure, like the Central Arizona Project, which was pushed through Congress by former U.S. Sen. Carl Hayden in 1968. It is the largest and one of the most expensive federal reclamation project in U.S. history.

"The federal government has a role," he said. "They can bring resources to bear that no state has the ability to do."

Flake disagreed with the notion earmarks are a good thing, saying there should be fair and open competition for federal money.

"A few of my colleagues went to jail because of the practice," Flake said. "And what was legal was even more pernicious. Campaign contributions in exchange for earmarks was rampant. The notion that we would want to go back to that kind of system is repugnant."

Flake said his efforts to eradicate earmarks has led to the state getting more money back in transportation funds. When he joined Congress, Arizona received about 88 cents on the dollar back of what it sent to the federal government.

He explained members of Congress in "donor states" like Arizona would accept earmarks in exchange for not fighting for more state funds, which allowed the state to continue to be short-changed.

The 2005 highway bill included about 6,300 earmarks, including what has become known as the "bridge to nowhere," Flake said.

But in the most recent 2012 highway bill, which covers seven years, the state will get back at least 95 cents on the dollar in tax revenues because of language Flake worked to get included in the legislation, and because earmarks are now prohibited, he said.

"That will mean hundreds of millions of dollars more for the state over the next four years," he said. "Arizona will get more funding in a more flexible manner."

Carmona pointed out earmarks represent less than 1 percent of the federal budget and that they still exist under a new mechanism. He said Flake's work to eradicate earmarks is part of why Congress is gridlocked.

"People stick their flag in the sand and say it's my way or the highway," Carmona said. "That's not what democracy is about. Democracy is about compromise."

About Flake, he said: "Whenever he's asked to do something in Washington, he says, 'That's an earmark. That's not my job."

Flake defends his work in Congress and says he's demonstrated he works across the aisle when dealing with issues that benefit the state.

Flake conceded there are still some earmark-type activities occurring on the margins in Congress, but legislators should work to ensure it doesn't become a common practice again. Even though earmarks represent a tiny portion of the budget, they leverage to higher spending.

"Once you get an earmark, you are obligated to support that piece of legislation no matter how bloated it becomes," Flake said. "We saw it again and again. That last thing we need to do is return to that era. It was an awful era, and it was Republicans and Democrats participating in it."

Carmona said the remedy for a system Flake loathes is transparency. He said he will be happy to explain why he backs a project and how it will benefit the state.

"Let the public see everything you are doing," he said. "It has to be done transparently, and it has to be done with integrity. We shouldn't abandon the process because others have been dishonest before. We should actually make it a more rigorous process and face it to the light of day."