President Donald Trump listens in the Diplomatic Reception Room of the White House in Washington, Monday, March 25, 2019, as Israeli Prime Minister Benjamin Netanyahu speaks. Trump signed an official proclamation formally recognizing Israel's sovereignty over the Golan Heights. (AP Photo/Susan Walsh)
Susan Walsh/AP
President Donald Trump listens in the Diplomatic Reception Room of the White House in Washington, Monday, March 25, 2019, as Israeli Prime Minister Benjamin Netanyahu speaks. Trump signed an official proclamation formally recognizing Israel's sovereignty over the Golan Heights. (AP Photo/Susan Walsh)
Now playing
02:00
Trump admin changes course on Affordable Care Act
CNN
Now playing
03:14
'Performative outrage': Avlon on GOP backlash to Rep. Waters
Two Honduran children found clinging to an island surrounded by a powerful current in the Rio Grande were rescued by Border Patrol agents and taken into custody, the region's top border official said, the latest example of the dangers migrants face as a growing number desperately attempt to reach the US.
U.S. Border Patrol
Two Honduran children found clinging to an island surrounded by a powerful current in the Rio Grande were rescued by Border Patrol agents and taken into custody, the region's top border official said, the latest example of the dangers migrants face as a growing number desperately attempt to reach the US.
Now playing
02:22
See Border Patrol rescue 2 migrant children in Rio Grande
Biden speaks from the Treaty Room in the White House on April 14, 2021 in Washington, DC.
Andrew Harnik/Pool/Getty Images
Biden speaks from the Treaty Room in the White House on April 14, 2021 in Washington, DC.
Now playing
02:59
Enten: Biden is focused on what Americans care about
CNN
Now playing
02:40
Biden says he's praying for 'right verdict' in Chauvin trial
ST. PAUL, MN - NOVEMBER 6:  Former U.S. Vice President Walter Mondale concedes the election to his Republican opponent Norm Coleman November 6, 2002 in St. Paul, Minnesota. Mondale and Coleman were in a race for U.S. Senate that was too close to call the evening before.  (Photo by Mark Erickson/Getty Images)
Mark Erickson/Getty Images
ST. PAUL, MN - NOVEMBER 6: Former U.S. Vice President Walter Mondale concedes the election to his Republican opponent Norm Coleman November 6, 2002 in St. Paul, Minnesota. Mondale and Coleman were in a race for U.S. Senate that was too close to call the evening before. (Photo by Mark Erickson/Getty Images)
Now playing
03:00
Walter Mondale dies at 93
george w bush congress immigration rhetoric cbs intv sot mxp vpx_00000000.png
george w bush congress immigration rhetoric cbs intv sot mxp vpx_00000000.png
Now playing
01:25
Bush calls on Congress to tone down 'harsh rhetoric' on immigration
WASHINGTON, DC - MARCH 23: Sen. Ted Cruz (R-TX) speaks at a Senate Judiciary Committee hearing on "Constitutional and Common Sense Steps to Reduce Gun Violence" on March 23, 2021 in Washington, DC.  Many senators spoke both for and against gun control the day after a shooting in Boulder, Colorado where a gunman opened fire at a grocery store, killing ten people. (Photo by Tasos Katopodis/Getty Images)
Tasos Katopodis/Getty Images
WASHINGTON, DC - MARCH 23: Sen. Ted Cruz (R-TX) speaks at a Senate Judiciary Committee hearing on "Constitutional and Common Sense Steps to Reduce Gun Violence" on March 23, 2021 in Washington, DC. Many senators spoke both for and against gun control the day after a shooting in Boulder, Colorado where a gunman opened fire at a grocery store, killing ten people. (Photo by Tasos Katopodis/Getty Images)
Now playing
03:18
Berman on Cruz's latest tweet: 'The pot calling the kettle violent'
Now playing
01:57
Chuck Hagel criticizes Trump's statement on Afghanistan
gun laws shootings Comer pamela brown nr vpx _00015627.png
CNN
gun laws shootings Comer pamela brown nr vpx _00015627.png
Now playing
02:23
'I can't answer that': Kentucky lawmaker responds to CNN on gun policy
Now playing
02:39
National security adviser: Russia will face consequences if Navalny dies in prison
Rep. Marjorie Taylor Greene (R-GA) speaks during a press conference outside the U.S. Capitol on February 5, 2021 in Washington, DC. The House voted 230 to 199 on Friday evening to remove Rep. Marjorie Taylor Greene (R-GA) from committee assignments over her remarks about QAnon and other conspiracy theories.
Drew Angerer/Getty Images
Rep. Marjorie Taylor Greene (R-GA) speaks during a press conference outside the U.S. Capitol on February 5, 2021 in Washington, DC. The House voted 230 to 199 on Friday evening to remove Rep. Marjorie Taylor Greene (R-GA) from committee assignments over her remarks about QAnon and other conspiracy theories.
Now playing
03:20
Marjorie Taylor Greene lashes out at media after backlash over controversial caucus
AP
Now playing
03:16
Maxine Waters: Jim Jordan is a bully and I shut him down
US Representative Marjorie Taylor Greene, Republican of Georgia, leaves her office on Capitol Hill on February 4, 2021 in Washington, DC.
NICHOLAS KAMM/AFP/Getty Images
US Representative Marjorie Taylor Greene, Republican of Georgia, leaves her office on Capitol Hill on February 4, 2021 in Washington, DC.
Now playing
03:51
Marjorie Taylor Greene launching 'America First' caucus
US President Joe Biden delivers remarks on Russia at the White House in Washington, DC on April 15, 2021. - The United States announced sanctions and the expulsion of 10 Russian diplomats Thursday in retaliation for what Washington says is the Kremlin's US election interference, a massive cyberattack and other hostile activity.
JIM WATSON/AFP/Getty Images
US President Joe Biden delivers remarks on Russia at the White House in Washington, DC on April 15, 2021. - The United States announced sanctions and the expulsion of 10 Russian diplomats Thursday in retaliation for what Washington says is the Kremlin's US election interference, a massive cyberattack and other hostile activity.
Now playing
02:22
White House backtracks on refugees decision after criticism
Biden speaks from the Treaty Room in the White House on April 14, 2021 in Washington, DC.
Andrew Harnik/Pool/Getty Images
Biden speaks from the Treaty Room in the White House on April 14, 2021 in Washington, DC.
Now playing
02:44
'National embarrassment': Biden reacts to mass shootings
(CNN) —  

Republican Sen. Susan Collins, a key swing vote in the Senate, is asking the Justice Department to reverse its recent support of a total strikedown of the Affordable Care Act, saying the job of eliminating aspects of the health care law should be left to Congress.

“Rather than seeking to have the courts invalidate the ACA, the proper route for the Administration to pursue would be to propose changes to the ACA or to once again seek its repeal. The Administration should not attempt to use the courts to bypass Congress,” Collins, who represents Maine, wrote in a letter sent Monday to Attorney General William Barr.

In a dramatic reversal last week, the Justice Department, in a filing with a federal appeals court, sided with the ruling of a federal judge in Texas that invalidated the Obama-era health care law last year.

The Texas ruling came after the Justice Department, under the direction of former Attorney General Jeff Sessions, argued that the community rating rule and the guaranteed issue requirement – protections for people with pre-existing conditions – could not be defended but the rest of the law, popularly known as Obamacare, could stand.

The shift in the Justice Department’s stance doubles down on stripping away the protections that were a hallmark of the landmark heath reform law.

In her letter to Barr, Collins said certain parts of the law – such as the penalty for not having insurance, which Congress effectively eliminated from the law in 2017 – could be jettisoned while others remained. The individual mandate requires nearly all Americans to have health insurance and had mandated those who didn’t to pay a penalty.

“It is implausible that Congress intended protections for those with preexisting conditions to stand or fall together with the individual mandate, when Congress affirmatively eliminated the penalty while leaving these and other critical consumer protections in place,” she wrote. “If Congress had intended to eliminate these consumer protections along with the individual mandate, it could have done so. It chose not to do so.”

Collins noted in her letter that the Justice Department’s new position “puts at risk not only critical consumer provisions” like the pre-existing conditions rule and “the Medicaid expansion, dependent coverage for young adults to age 26, coverage for preventive services, and the regulatory pathway for FDA approval of biosimilars.”

In September 2017, Collins was one of three Republicans who were opposed to a GOP-sponsored effort to repeal Obamacare, expressing concerns that the legislation didn’t do enough to protect individuals with pre-existing conditions.

CLARIFICATION: This story has been updated to clarify that Congress effectively eliminated the penalty for not having insurance, rather than the requirement altogether.

CNN’s Ariane de Vogue and Tami Luhby contributed to this report.