The Washington Post has broken the latest story about Sen. Warren's claims of "American Indian" heritage. She could have prevented this latest embarrassment.

The political media and the opponents of Sen. Elizabeth Warren, a Massachusetts Democrat, has been going on for years. It first surfaced when she successfully challenged then-Republican Senator Scott Brown. President Trump picked up on the issue and branded her "Pocahontas," following his friend Howie Carr's lead with the title "Fake Indian."

Last year, the senator and wannabe president revealed her DNA test showed she was Native American. Unfortunately, she was less American Indian then the average person living in the United States today. The way she did the reveal was over the top and only hurt her credibility with the public.

Now, the Washington Post has discovered "Warren’s registration card for the State Bar of Texas, providing a previously undisclosed example of Warren identifying as an “American Indian' Warren filled out the card by hand in neat blue ink and signed it. Dated April 1986, it is the first document to surface showing Warren making the claim in her own handwriting. Her office didn’t dispute its authenticity."

Senator Warren certainly knew she filled out this card and has a copy of it in her professional records. This document should have come out with the DNA test rollout. Did she share it with her political staff? After years of dealing with this issue, the senator and her team shouldn't have let someone else deliver this information to the public.

The Republicans also should be embarrassed by the discovery of this document. She has been through two elections for the United States Senate and is constantly at war with President Trump. How did the GOP not discover this document in Texas?

Running for office as a Democrat in Massachusetts is not the same as running for president, and the supporters of Sen. Warren have reasons to be concerned about her abilities as a candidate and a decision maker.

Chris McCarthy is the host of The Chris McCarthy Show on 1420 WBSM New Bedford. He can be heard weekdays from 10 a.m. to noon. Contact him at chris.mccarthy@townsquaremedia.com and follow him on Twitter @Chris_topher_Mc. The opinions expressed in this commentary are solely those of the author.