Patrick McMullen is what is known in laymen's terms as a Weed Scientist.
A specialist in his field, McMullan tests herbicides, insecticides, and fertilizers to see how they effect various crops--like winter wheat.
McMullan has been working for Agro-technology Research in Memphis for two years, and he's still trying to get his green card to establish permanent residency in the U.S.
"Currently I'm employed through what is called an H1B Work Visa," he said. "It permits me to work specifically for one company for three years."
Before McMullan can apply for a green card, his employer has to prove that no one in the U-S is qualified for the job and wants to work in Memphis.
The company has even posted McMullan's position in the classifieds. All of this has to be documented with the Tennessee Department of Labor, and the Department of Homeland Security.
It is a process that could take three years.
"I see no reason to flaunt the law," McMullan said. "Hopefully my qualifications will stand out enough that I can stay here."
So McMullan is frustrated by rallies, like that was held Monday in downtown Memphis, where thousands of people push for rights for people who choose to come the country illegally.
McMullan is even more frustrated with congressional lawmakers.