Undocumented immigrants and advocacy groups react to Wednesday's election outcome with trending hashtag #HereToStay. Reuters

Following Donald Trump’s presidential win, thousands of undocumented immigrants face an increasingly plausible threat of deportation.

With Trump’s campaign promise to remove undocumented immigrants from the U.S. with the help of a “deportation force” and to build a wall along the U.S.-Mexico border, many now fear mass deportation. But fear hasn’t gotten the best of many.

Following the election results early Wednesday morning, a hashtag began trending on Twitter, #HereToStay, where many undocumented immigrants took to social media to pledge that they would not be going anywhere.

“We are still undocumented, unafraid and unashamed,” one hashtag user pledged.

“I’m going to tell my kids that in 2017, we fought back and protected each other,” another Twitter user wrote.

Under the president-elect's proposed deportation plan, as many as 11 million undocumented immigrants could face deportation.

Anywhere from 5 million to 6.5 million from the 11 million undocumented immigrants in the U.S. would be prioritized for removal, according to NBC. Trump has promised to strike down Deferred Action for Childhood Arrivals (DACA) an executive action that was passed by President Barack Obama in 2012. The action currently allows undocumented immigrants who entered the U.S. before June 2007 or before their 16th birthday to have “deferred action status” for a period of two years and to be eligible for employment for two years, both of which would be renewable. If the program ends, more than 700,000 immigrants could cease working in the U.S. and be deported, according to NBC News.

Pro-immigration advocacy groups have demanded retribution and are urging people to stand together.

“Immigrants are declaring a state of urgency and resilience,” co-founder of immigration advocacy group United We Dream, Cristina Jimenez said in a statement. “Over the coming weeks, our families and community members will need to tap into the incredible strength that brought us to this country and which we use to survive.”