Oprah Winfrey backs John Fetterman over Dr. Mehmet Oz in Pennsylvania Senate race

Oprah Winfrey said Thursday she would vote for Democratic Lt. Gov. John Fetterman over Republican Dr. Mehmet Oz in the must-win Senate race in Pennsylvania.

It's a notable snub for Oz, a former talk-show host backed by former President Donald Trump who became a celebrity doctor and a household name largely through his association with Winfrey.

Herself a talk-show superstar and media titan, Winfrey was the first guest on Oz's early-2000s show "Second Opinion," and she invited Oz on "The Oprah Winfrey Show" regularly for years. Her company launched "The Dr. Oz Show," which ran for 13 seasons and ended in January.

But Winfrey endorsed Fetterman, along with a slate of other Democrats in high-profile Senate races, during a virtual get-out-the-vote event Thursday evening.

"I will tell you all this, if I lived in Pennsylvania, I would have already cast my vote for John Fetterman for many reasons," Oprah said.

With less than a week until Election Day, polls show Fetterman and Oz are in a dead heat in the Keystone State. The race for the Senate seat left open by the retirement of GOP Sen. Pat Toomey is seen as one of the most competitive in the country, as Democrats look to defend their narrow Senate majority.

Fetterman, who is recovering after suffering a life-threatening stroke in May, has slammed Oz as an out-of-touch elitist and a carpetbagger from New Jersey. Oz has accused Fetterman of being too far left for the swing state and soft on crime and has questioned whether he is healthy enough to serve as senator.

"And that is not the only race that matters," Winfrey said. She said that if she could she would vote for Democrat Cheri Beasley over GOP Rep. Ted Budd in North Carolina, and for Val Demings, Florida Sen. Marco Rubio's Democratic challenger.

In the same breath, Winfrey backed: Democratic Lt. Gov. Mandela Barnes over incumbent Sen. Ron Johnson in Wisconsin; Democratic Sen. Catherine Cortez Masto over GOP hopeful Adam Laxalt in Nevada; and Sen. Raphael Warnock over Republican Herschel Walker in Georgia.

Winfrey also said she would vote for Texas gubernatorial candidate Beto O'Rourke, a Democrat, over incumbent Republican Gov. Greg Abbott, as well as Stacey Abrams, the Democrat running to unseat Republican Gov. Brian Kemp in Georgia.

"So there are clear choices out there and some dynamic candidates who are working to represent the values — this is what we're talking about — the values that we hold dear, the values of inclusion, the values of compassion and community that so many of us share," Winfrey said.

"So use your discernment, which seems to be missing in a lot of our country today. Use your discernment and choose wisely for the democracy of our country," she added.

Fetterman in a statement called it "an honor and privilege to have Oprah's support in this race."

"She is a leader on so many issues — fighting for our democracy, passing common-sense gun reform, and ensuring racial justice," Fetterman said. "I'm grateful for Oprah's support and trust on the issues that matter to people across the country and Pennsylvania as we close out this campaign."

A spokeswoman for Oz's campaign did not immediately respond to CNBC's request for comment on Winfrey's endorsement. In a statement to NBC News, his campaign said, "Doctor Oz loves Oprah and respects the fact that they have different politics. He believes we need more balance and less extremism in Washington."