The Star invited Arizona's three U.S. Senate candidates to answer that question, based on the following background:

Mexico is Arizona's top export partner, accounting for more than a third of our state's foreign trade. Yet the total value of our exports to Mexico has grown by 1 percent over the past four years while Texas has increased its total by 40 percent. What does Arizona need to do better and how will you expedite trade across our state's border?

This is the second of three Sundays of guest commentaries by the Senate candidates. You can read last week's question about jobs at

One of the least talked about and most important drivers of Arizona's economy is our relationship with Mexico.

Arizona exported $5.97 billion in goods to Mexico in 2011. And according to the Chamber of Commerce, more than 110,000 Arizona jobs are dependent on our trade relationship.

Unfortunately, that crucial piece of Arizona's economy hasn't been growing. In 2009, our exports to Mexico actually decreased. And since then, there have only been slight upticks.

Arizona has tried small steps to incentivize exporters, but what we really need is to improve our relationship with Mexico. I credit Tucson Mayor Jonathan Rothschild and Phoenix Mayor Greg Stanton for recently traveling to Mexico to build relationships and encourage trade - but we need more leaders in our state focused on building and maintaining these critical relationships.

There are 23 states that have offices throughout Mexico to encourage trade - Arizona isn't currently one of them. And many of our exports to Mexico only make it to the border state of Sonora, so they don't break into Mexico's largest markets.

While Arizona has struggled to gain traction in Mexico, other states have seen their trade grow significantly over the last few years. In trying to assess why our state isn't as strong of a trade partner, it's hard to ignore the vitriol and heated rhetoric that comes from our state officials.

Like most Arizonans, I am deeply frustrated by the federal government's failure to solve our immigration problem. But unlike our career politicians, I don't see our situation as an issue for dividing the electorate. I see this issue through my experience as a deputy sheriff in a border county, from running hospitals in Southern Arizona and from working to solve health problems on both sides of the border. And with that experience, I know our political problems over immigration have turned into economic and trade ones with Mexico.

The fact is, the issue that we boil down to "immigration" is really a deeply complex situation that involves security, culture, history and economics. And while our immigration problems are complicated, the rational and achievable solution is simple: secure the border, develop a pathway to earn legal status and enact the DREAM Act.

Leadership on this issue takes courage, but it also requires politicians to stop using immigration as a wedge issue to score political points. And like on many issues, our solution won't come from one party or the other - we need leaders from both sides to step up and do something bigger than their personal politics.

Democrat Richard Carmona is vice chairman of Canyon Ranch Institute; a professor in the Arizona College of Public Health; and a deputy Pima County sheriff.