If you are among the millions who receive emails from President Barack Obama supporters, then you’re probably aware of a recent one from Mayor Julian Castro of San Antonio. In the email, the mayor makes the case for immigration reform by explaining the situation his grandmother encountered years ago.

“My grandma came to the United States as an orphan from Mexico,” he said. “She never made it past the fourth grade–she had to drop out of school to work and support her family. As an adult, she scraped by, working hard to give my mother a shot, so that my mother could give my brother and me an even better one.”

He continued by stating that immigrants like his grandmother “have helped build this country. They deserve a system that works–and our country’s economy depends on it. We know what’s broken, and we know how to fix it.”

Over the last several months, a bipartisan “Group of Eight” senators have been working diligently to repair the broken system, and while they have apparently solved many of the major stumbling blocks, there remain a few troubling issues. It was reported last week that the U.S. Chamber of Commerce and the AFL-CIO, two major negotiators in the process, have reached an agreement on the guest-worker program, thereby removing a huge obstacle in getting a full immigration bill. But until things are settled on the pay rate for agricultural workers and the cap on their number available to growers, the senators still face an enormous impasse.

The sticking point amounts to unions seeking to protect their workers with fair wages while the growers insist on an unlimited number of workers, which could make it easier to exploit the farmworkers. If wages are too high, the growers contend, the program will fall apart. On the other hand, if the visa cap is too low, there won’t be enough workers for the crops.

According to the latest reports, the Group of Eight is tackling this problem by proposing a plan that will vary from one region to another. Additionally, wages would vary from worker to worker, depending on whether they are pickers or operating machines. The unions seem to be basically satisfied with the agreement put forth by the senators, but the growers have yet to come aboard.

A compromise would appear to be the only way to reach an accord with the growers, and then perhaps a full bill can come into effect that would, as Castro hopes, “strengthen border security, streamline the legal immigration process so law-abiding companies can get the workers they need and create an earned path to citizenship for the 11 million undocumented immigrants living in the shadows.”