You might think that Mexico leads the way in numbers of legal and illegal immigrants coming to the United States. And for many decades, that was true.

But in the last 10 years, the trend of immigration has shown that China and India have surpassed Mexcio in numbers of immigrants, adding a new wrinkle to the immigration debate.

Associated Press:

Siddharth Jaganath wanted to return to India after earning his master's degree at Texas' Southern Methodist University. Instead, he built a new life in the U.S. over a decade, becoming a manager at a communications technology company and starting a family in the Dallas suburb of Plano.

"You start growing your roots and eventually end up staying here," the 37-year-old said.

His path is an increasingly common one: Immigrants from China and India, many with student or work visas, have overtaken Mexicans as the largest groups coming into the U.S., according to U.S. Census Bureau research released in May. The shift has been building for more than a decade and experts say it's bringing more highly skilled immigrants here. And some Republican presidential candidates have proposed a heavier focus on employment-based migration, which could accelerate traditionally slow changes to the country's ever-evolving face of immigration.

Mexicans still dominate the overall composition of immigrants in the U.S., accounting for more than a quarter of the foreign-born people. But of the 1.2 million newly arrived immigrants here legally and illegally counted in 2013 numbers, China led with 147,000, followed by India with 129,000 and Mexico with 125,000. It's a sharp contrast to 2000, when there were 402,000 from Mexico and no more than 84,000 each from India and China. Experts say part of the reason for the decrease in Mexican immigrants is a dramatic plunge in illegal immigration.

"We're not likely to see Asians overtake Latin Americans anytime soon (in overall immigration population). But we are sort of at the leading edge of this transition where Asians will represent a larger and larger share of the U.S. foreign-born population," said Marc Rosenblum, deputy director of the U.S. Immigration Policy Program for the Washington-based Migration Policy Institute.

Part of the immigration debate this year has been the question of guest worker visas and legal entry for highly educated tech workers. There is some anecodotal evidence that American firms are abusing these programs to hire foreign workers at the expense of Americans, but trends are difficult to see. That's why both these programs are in desperate need of reform. At present, we graduate enough tech workers to fill the slots in industry that open every year. But the numbers of engineers, scientists, and mathematicians graduating has been falling for a decade and by 2020, a need will exist to bring STEM workers here from overseas to keep the US competitive. 

Because of the excellence of our schools, foreigners flock to the US to receive advanced degrees in the STEM fields. These are people who want to be here and would have no trouble finding work. The question being asked is do they take jobs from Americans because they're cheaper to hire?

These are hyper-competitive fields that American companies would lose out in hiring if they offered less than firms in Japan, Indonesia, or the EU countries. But current law makes it more difficult for the best of the best to come here to contribute to the US economy.Hence, the need for reform to make sure we have an adquate number of highly skilled tech workers in the near future.

It's not surprising that China and India would lead the way in immigration. Sending us their best and brightest should be seen as a gift, not a burden.