President Donald Trump has taken a hard stance on immigration since day one of his campaign. From his beloved border wall to his harsh words against Mexican immigrants, one of his most prominent talking points is a crackdown on immigration.

Outside of “illegal immigration,” Trump has shifted his sights to changing the H-1B visa program. Below is a brief timeline of the Trump administration’s attack on H-1B visas:

April 2017

On April 17, President Trump signed the “Buy American, Hire American” Executive Order while speaking at a tools manufacturer in Kenosha, Wisconsin. The order is meant to direct federal agencies to review and propose changes to the H-1B visa program as well as maximizing the amount of American-made products — such as steel, iron, aluminum and cement — that they purchase.

September 2017

Data reviewed by Reuters shows that the Trump administration is challenging more visa applications than previous administrations, making it more difficult for skilled foreign workers to work in the United States.

U.S. Citizen and Immigration Services (USCIS) data reveals that it issued some 85,000 requests for evidence, a 45 percent increase from the same period last year. The requests can make it harder for employers to receive H-1B visas since they typically must provide additional evidence proving their eligibility as well as why they require the visas.

October 2017

In October, USCIS updated its policies to “instruct officers to apply the same level of scrutiny to both initial petitions and extension requests from certain nonimmigrant visa categories.” Not only could the update make visa renewal more costly for employers hiring foreign workers, but it has also been criticized as making the process unnecessarily hard to prompt employers to hire more Americans instead of foreign workers.

December 2017

The Department of Homeland Security could consider regulations to prevent H-1B visa extensions as part of a proposal drafted as part of the “Buy American, Hire American” executive order. Hundreds of thousands of foreign workers could potentially lose their H-1B status while waiting for the immigrant visa quota to move forward so they can file their green card applications.

 January 2018

USCIS reversed its proposal to essentially force skilled foreign workers out of the country, stating, “… USCIS is not considering a regulatory change that would force H-1B visa holders to leave the United States by changing our interpretation of section 104(c) of AC-21, which provides for H-1B extensions beyond the 6 year limit.”

Donald Trump’s views on immigration views are strong and clear — from overtly racist to plain hopelessly uninformed. By targeting skilled foreign workers — many of whom are necessary in the tech industries — Trump is not only showing his bias against immigrants, but also obstructing the possibility economic growth for both U.S-born and foreign workers in the booming technology sector.