WASHINGTON, DC - APRIL 17:  George T. Conway III, husband of White House Counselor to the President Kellyanne Conway, attends the 139th Easter Egg Roll on the South Lawn of the White House April 17, 2017 in Washington, DC. The White House said 21,000 people are expected to attend the annual tradition of rolling colored eggs down the White House lawn that was started by President Rutherford B. Hayes in 1878.  (Photo by Chip Somodevilla/Getty Images)
Chip Somodevilla/Getty Images
WASHINGTON, DC - APRIL 17: George T. Conway III, husband of White House Counselor to the President Kellyanne Conway, attends the 139th Easter Egg Roll on the South Lawn of the White House April 17, 2017 in Washington, DC. The White House said 21,000 people are expected to attend the annual tradition of rolling colored eggs down the White House lawn that was started by President Rutherford B. Hayes in 1878. (Photo by Chip Somodevilla/Getty Images)
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Attorney George Conway, the husband of White House counselor Kellyanne Conway, called President Donald Trump’s proposal to end birthright citizenship “unconstitutional” in a Washington Post op-ed he co-wrote Tuesday.

“Sometimes the Constitution’s text is plain as day and bars what politicians seek to do. That’s the case with President Trump’s proposal to end ‘birthright citizenship’ through an executive order,” Conway writes, along with Obama-era US Solicitor General Neal Katyal. The duo argues this is due to the 14th Amendment.

“Such a move would be unconstitutional and would certainly be challenged. And the challengers would undoubtedly win,” they added.

George Conway’s stance contrasted with that of his wife. Kellyanne Conway told reporters Tuesday that “there are constitutional scholars that say the 14th Amendment has been misinterpreted, and, actually, the Supreme Court has never gave a solid opinion on this.”

Trump told Axios in an interview released Tuesday morning that he was in the process of ending birthright citizenship through an executive order.

“They’re saying I can do it just with an executive order,” Trump said, later adding, “It’s in the process. It’ll happen … with an executive order.”

The 14th Amendment, added to the Constitution in 1868, says that “all persons born or naturalized in the United States and subject to the jurisdiction thereof, are citizens of the United States.”

The lawyers argue that the 14th Amendment arose in the aftermath of the Dred Scott Supreme Court case in 1857, which ruled that slaves and their children could not be US citizens.

“What they wrote was simple and clear,” George Conway and Katyal write. “Both proponents and opponents of the language at the time knew exactly what it meant: Virtually anyone born in the United States is a citizen.”

The pair adds that in 1898, the court upheld the understanding that the 14th Amendment included “all children here born of resident aliens,” with the only exemptions being “children born of alien enemies in hostile occupation, and children of diplomatic representatives of a foreign state.”

George Conway and Katyal reminded readers of Trump’s pledge to nominate judges in the image of late Supreme Court Justice Antonin Scalia, a staunch originalist committed to interpreting the Constitution as written.

“To say that he would have declared it dead on arrival would be an understatement,” the duo writes. “Whatever one may think of the merits of adding a further exception to the 14th Amendment’s guarantee of birthright citizenship … the simple fact is that the amendment, as written, doesn’t permit it.”

Kellyanne Conway told Fox News on Tuesday morning that birthright citizenship was being “misused.”

“Europe doesn’t have that – France ended theirs in 1993 – and most parts of Asia, many parts of Asia don’t have it,” she said. “So many others, constitutional scholars, have argued that the 14th Amendment has been misinterpreted or misused in this way.”

The issue of birthright citizenship is yet another iteration of the couple supporting differing views in public. George Conway, a frequent Twitter user, cheered on criticism of Trump’s blasting of the media as “enemies of the people” on Monday, tweeting, “yes, pile away.” He has also pushed back on Trump’s attacks on Attorney General Jeff Sessions.