An Oklahoma Republican and enrolled member of the Cherokee Nation said Sen. Elizabeth Warren has been "caught in a lie" and she should abandon her plans to enter the 2020 presidential race.

Rep. Markwayne Mullin (R-Okla.), the only Cherokee Nation citizen in Congress, joined Ainsley Earhardt on "Fox & Friends" Friday morning to react to the latest revelation in Warren's (D-Mass.) Native American heritage controversy.

The Washington Post reported Tuesday that Warren indicated that her race was "American Indian" in a handwritten registration form filed in 1986 with the Texas State Bar, which is the first known instance of Warren claiming Native American ancestry in an official document or in her own handwriting.

Warren has been accused by Republicans, including President Trump, of claiming Native American heritage to bolster her academic career.

In October, Warren released a DNA test that revealed "strong evidence" of a Native American ancestor dating back six to ten generations, which would make her between 1/64th and 1/1,024th Native American.

Last week, Warren apologized to the Cherokee Nation for taking the DNA test in an attempt to prove her ancestry claims, and on Tuesday, she again more broadly apologized for identifying as Native American for decades, according to The Post.

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Mullin said that Warren "absolutely" used her heritage claims to get ahead professionally, and he believes she should be disbarred in Texas.

"She got caught in a lie," Mullin said. "It's obvious. It's in black and white. She wrote it in her own handwriting that she was 'American Indian.'"

"Now that she's caught, what she just needs to do is step back and say, 'Look, I'm not qualified even run for president,'" he said.

Earhardt noted that Warren has repeatedly apologized, and Mullin said he forgives her, but that doesn't mean she should be able to move forward with her political career.

"She didn't have the character to be president before this came to light. This just shows another flaw in her character."

Watch the "Fox & Friends" interview above.

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