President Trump's family separation policy for illegal immigrants at the U.S.-Mexico border has sparked public outrage among Republican lawmakers.

Why it matters: This wave of Republican rejection puts the Trump administration in a difficult position as House Republicans consider two immigration bills this week — one of which would address the issue, but would likely need Trump's support to be successful.

Sen. Lindsey Graham said President Trump could "stop this policy with a phone call" on Friday in an interview with CNN. "I'll go tell him. If you don't like families being separated, you can tell DHS stop doing it."

said President Trump could "stop this policy with a phone call" on Friday in an interview with CNN. "I'll go tell him. If you don't like families being separated, you can tell DHS stop doing it." Sen. Ben Sasse outlined his feelings on Facebook but gave his "short version" in a tweet: "While there's much to say about how catch-and-release policies led us here, family separation is wicked & needs to be stopped "

outlined his feelings on Facebook but gave his "short version" in a tweet: "While there's much to say about how catch-and-release policies led us here, family separation is wicked & needs to be stopped " Sen. Susan Collins said on CBS' "Face the Nation" that the policy is "traumatizing to the children who are innocent victims" and "contrary" to the values of the country.

said on CBS' "Face the Nation" that the policy is "traumatizing to the children who are innocent victims" and "contrary" to the values of the country. Sen. Jeff Flake , along with Collins, wrote a letter to the Departments of Homeland Security and Health and Human Services with questions about the family separation policy as it applies to asylum seekers.

, along with Collins, wrote a letter to the Departments of Homeland Security and Health and Human Services with questions about the family separation policy as it applies to asylum seekers. Rep. Mark Meadows said "families need to be unified" and that legislators need to "get to the bottom of it and make sure families stay together" in an interview with MSNBC's Chris Hayes.

said "families need to be unified" and that legislators need to "get to the bottom of it and make sure families stay together" in an interview with MSNBC's Chris Hayes. Rep. Will Hurd , whose district includes a long stretch of the U.S.-Mexico border, called the policy "unacceptable" and said children should not be used as a "deterrent policy" in the "home of the free and land of the brave," in an interview with CNN.

, whose district includes a long stretch of the U.S.-Mexico border, called the policy "unacceptable" and said children should not be used as a "deterrent policy" in the "home of the free and land of the brave," in an interview with CNN. Sen. James Lankford tweeted that he disagrees with the policy, adding that he believes "we must continue to protect the privacy of the children."

Former First Lady Laura Bush jumped into the fray yesterday, stating that the policy "breaks her heart" and comparing it to the internment of Japanese-Americans during World War II. First Lady Melania Trump also issued a statement via her spokeswoman yesterday, saying that the United States needs "to be a country that follows all laws, but also a country that governs with heart."

Go deeper: Pressure grows on Trump to change border policy for kids.