01:22 - Source: CNN
Homeland Security Secretary Kirstjen Nielsen resigns
Washington CNN —  

President Donald Trump announced Sunday that Department of Homeland Security Secretary Kirstjen Nielsen would be leaving her role in the Trump administration.

The departure comes as department and immigration officials have claimed that an influx of migrants attempting to come in to the US has pushed their systems at a breaking point, leading Trump to declare a national emergency and threaten to shut down the southern border earlier this month.

While Trump said Customs and Border Protection Commissioner Kevin McAleenan will fill Nielsen’s role in an acting capacity, a number of names are being floated for the agency’s permanent replacement.

Though, as one White House official told CNN’s Pamela Brown, there’s also concern no one will want to serve as Nielsen’s replacement. And whoever is picked will surely face a tight confirmation vote in the Senate, which Republicans narrowly control.

Ken Cuccinelli

Ken Cuccinelli
Ken Cuccinelli
Ken Cuccinelli

Cuccinelli, the former Virginia attorney general and Republican gubernatorial candidate, is one of the hardliners being considered for the position. He is also among the individuals being floated to fill a new role being considered by the White House: immigration czar.

As Virginia’s attorney general, Cuccinelli signed onto an amicus brief which supported SB 1070, an Arizona immigration law which permitted law enforcement to inquire about someone’s immigration status when they’re stopped, detained or arrested. He also issued a legal opinion which argued that Virginia law enforcement could also inquire about someone’s immigration status when they’re stopped.

While serving as a state legislature in Virginia, Cuccinelli worked on legislation that would have established someone’s inability or refusal to speak English on the job as a form of misconduct that would bar them from receiving unemployment benefits, and would amend the Constitution to deny citizenship to children born in the US whose parents are undocumented immigrants.

Last fall, Trump told the press he’d like to end birthright citizenship.

Cuccinelli is a CNN political commentator.

Tom Homan

Thomas Homan, acting director of Immigration and Customs Enforcement, delivers remarks during a law enforcement roundtable on sanctuary cities held by President Donald Trump, in the Roosevelt Room at the White House on March 20, 2018 in Washington, D.C. Credit: Kevin Dietsch / Pool via CNP - NO WIRE SERVICE ' Photo by: Kevin Dietsch/picture-alliance/dpa/AP Images
Kevin Dietsch/dpa/AP
Thomas Homan, acting director of Immigration and Customs Enforcement, delivers remarks during a law enforcement roundtable on sanctuary cities held by President Donald Trump, in the Roosevelt Room at the White House on March 20, 2018 in Washington, D.C. Credit: Kevin Dietsch / Pool via CNP - NO WIRE SERVICE ' Photo by: Kevin Dietsch/picture-alliance/dpa/AP Images

Homan, a career law enforcement officer, is the former acting director of Immigration and Customs Enforcement. He announced his plans to retire in 2018, and shortly after leaving the agency, he jumped to Fox News to be a contributor on the network.

He was formally nominated for the ICE director role in 2017, but he was never confirmed. With the recent withdrawal of Ron Vitiello’s nomination to lead ICE, the agency has remained without a permanent director for more than two years.

Homan has been a steadfast defender of the President’s immigration enforcement policies.

Most recently, Homan defended Trump’s decision to name McAleenan to lead the Department of Homeland Security as acting secretary.

Rick Perry

WASHINGTON, DC - JANUARY 19: Former Texas Governor Rick Perry, President-elect Donald TrumpÕs choice as Secretary of Energy, testifies during his confirmation hearing before the Senate Committee on Energy and Natural Resources on Capitol Hill January 19, 2017 in Washington, DC. Perry is expected to face questions about his connections to the oil and gas industry.   (Photo by Aaron P. Bernstein/Getty Images)
Aaron P. Bernstein/Getty Images North America/Getty Images
WASHINGTON, DC - JANUARY 19: Former Texas Governor Rick Perry, President-elect Donald TrumpÕs choice as Secretary of Energy, testifies during his confirmation hearing before the Senate Committee on Energy and Natural Resources on Capitol Hill January 19, 2017 in Washington, DC. Perry is expected to face questions about his connections to the oil and gas industry. (Photo by Aaron P. Bernstein/Getty Images)

Energy Secretary Rick Perry is also reportedly in the mix as a potential Nielsen replacement.

The former Texas governor is well acquainted with immigration policy having led the large border state for years. But he railed against Trump during the 2016 Republican presidential primary, calling the Trump a “cancer” on conservatism and a “carnival barker.” As an opponent in the presidential race, he also criticized Trump’s call for a border wall and said he had a “fundamental misunderstanding” of immigration issues.

He also said a physical border wall was never going to happen.

But Trump seems to have forgiven those words when he tapped Perry to lead his Energy Department.

An Energy Department official, however, pushed against the idea that Perry could be switching departments.

“Secretary Perry is very happy where is, leading the Department of Energy,” the official said.

Emilio Gonzalez

Gonzalez is currently the city manager and chief administration officer of Miami.

He served in many several immigration and national security roles during George W. Bush’s presidency. He was the director of US Citizenship and Immigration Services, the office within the Department of Homeland Security, which works on federal immigration and naturalization processes, from 2005-2009. He also served as director for Western Hemisphere Affairs at the National Security Council during the Bush administration.

Nielsen’s departure comes as the White House also considers removing the current director of US Citizenship and Immigration Services, Lee Cissna, from his post.

Kris Kobach

US President Donald Trump waves after speaking alongside Kansas Secretary of State Kris Kobach (L) during the first meeting of the Presidential Advisory Commission on Election Integrity in the Eisenhower Executive Office Building next to the White House in Washington, DC, July 19, 2017. / AFP PHOTO / SAUL LOEB        (Photo credit should read SAUL LOEB/AFP/Getty Images)
SAUL LOEB/AFP/AFP/Getty Images
US President Donald Trump waves after speaking alongside Kansas Secretary of State Kris Kobach (L) during the first meeting of the Presidential Advisory Commission on Election Integrity in the Eisenhower Executive Office Building next to the White House in Washington, DC, July 19, 2017. / AFP PHOTO / SAUL LOEB (Photo credit should read SAUL LOEB/AFP/Getty Images)

The former Kansas secretary of state enacted some of the harshest voter ID laws in the country during his tenure in state leadership. Last year, Kobach was defeated in a run for Kansas governor.

Kobach previously spearheaded a Trump White House committee on election integrity. The commission, started during the first year of the Trump administration, was disbanded when it became ensnared with legal challenges.

Kobach is also among the list of people being floated to become the White House immigration czar. He told Fox Business Network Monday morning that “it’s possible that the White House might want a border czar in addition to a new … Homeland Security secretary,” but also conceded that the czar position might not be necessary if the right person was leading the department.

“If (the President) decides that it’d be right for the country for me to serve, I’d be honored to do so,” Kobach said, when asked if he would take the czar position.

During the presidential transition, Kobach’s name was being floated to lead the Department of Homeland Security. While he didn’t ultimately get the job, he was photographed with the President, holding a paper which appeared to reveal his plans for the department.

Pam Bondi

JACKSONVILLE, FL - AUGUST 03:  Florida Attorney General Pam Bondi speaks prior to Republican presidential nominee Donald Trump arriving on stage for a rally at the Jacksonville Veterans Memorial Arena on August 3, 2016 in Jacksonville, Florida. Trump has had to answer concerns from inside the Republican party that his campaign is in disarray. (Photo by Mark Wallheiser/Getty Images)
Mark Wallheiser/Getty Images North America/Getty Images
JACKSONVILLE, FL - AUGUST 03: Florida Attorney General Pam Bondi speaks prior to Republican presidential nominee Donald Trump arriving on stage for a rally at the Jacksonville Veterans Memorial Arena on August 3, 2016 in Jacksonville, Florida. Trump has had to answer concerns from inside the Republican party that his campaign is in disarray. (Photo by Mark Wallheiser/Getty Images)

The former attorney general of Florida was an ardent supporter of Trump during the 2016 presidential race.

While she was Florida’s attorney general, she was one of several state attorneys general to sign onto a challenge to then-President Barack Obama’s executive action to implement the Deferred Action for Childhood Arrivals program.

While still serving as Florida’s top cop in 2018, her office refused to join a lawsuit with 17 states attempting to force the Trump administration to reunite migrant families, saying her office didn’t have jurisdiction in the matter.

Bondi also joined an amicus brief supporting Arizona’s SB 1070 law.

CNN’s Priscilla Alvarez, Geneva Sands and Michael Warren contributed to this report.