Decorated Air Force veteran MJ Hegar is running for Congress, and she's out with a powerful new ad some are calling 'the best political ad anyone's ever seen.'

Deep in the heart of Texas, Mary Jennings “MJ” Hegar — the decorated war hero and Democratic nominee taking on eight-term birther congressman John Carter — has gone viral.

Hegar released the powerful new ad “Doors” last week, and using doors as a metaphor, she tells the story of the challenges she has faced, and overcome, throughout her life. And the ad is making a huge splash.

As of Monday, it has generated over 3.5 million views on Facebook and YouTube and over 20,000 comments. Lin-Manuel Miranda, the creator of the Broadway hit “Hamilton,” called it “the best political ad anyone’s ever seen.”

The ad talks about all of the doors that were closed to Hegar and details the ways she challenged those in power to open the doors for herself and others.

“This door behind me is from my helicopter. It’s all that’s left of the aircraft that I was flying that day,” she says. “I was on a rescue mission in Afghanistan as a combat search and rescue pilot. I heard the windshield crack and realized I’d been shot. I continued the mission and airlifted the patients out. After taking even more fire we crashed a few miles away.”

Hegar goes on to describe her successful fight to lift the military’s ban on women in ground combat, and how many politicians slammed the door in her face.

“I was treated like I was not important because I was not a donor,” she said. One congressman who turned her away was Carter himself.

“Congressman Carter hasn’t had a tough race his entire career,” she concludes. “So we’ll show him tough. Then we’ll show him the door.”

Carter, who has served in Congress for 15 years, is a tea party supporter and birther who cosponsored a bill in 2009 to require presidential candidates to provide their original birth certificates — a blatantly racist attack on President Obama. Even after Obama released his birth certificate in 2011, Carter attacked him for not doing so sooner.

Carter is also vehemently opposed to immigration. He supported the nativist “Minuteman Project” and said in a recent bizarre speech during a border security hearing that “a lot of the attractive children are not making it to the border.”

The 31st District includes Fort Hood, one of the largest U.S. military installations in the world. Carter won his last election there by over 20 points.

Last November, one poll showed Hegar within 6 points of Carter. Shortly after the ad’s release, the Cook Political Report deemed the race no longer “Solid Republican.”

It’s still an uphill battle to flip a reliably red district. But with Hegar’s powerful life story, incredible record of military service, and inspiring campaign — not to mention predictions that a massive blue wave is coming in November — Carter might start worrying about how safe his seat really is.