Democrat Phil Bredesen, a popular moderate running for U.S. Senate in Tennessee, says he would not back New York's Chuck Schumer to lead the party in the chamber.

The pledge is the former governor's largest break from the national Democratic Party as he tries to flip a seat in a solidly Republican state. Bredesen has tried to build an independent brand during his campaign. He made the claim Tuesday during opening remarks at his first debate with Republican candidate Rep. Marsha Blackburn.

Bredesen said Washington has become "hyperpartisan" and needs fresh leadership, whether it's on the Democratic or Republican side of the aisle.

"We need to get new leadership. I can tell you right now that if I'm elected, and when I'm elected and go to Washington, I am not going to be voting for Chuck Schumer," Bredesen said of the Senate's top Democrat.

Bredesen joins other Democratic Senate candidates trying to flip GOP-held seats who have vowed to vote against the minority leader. Rep. Beto O'Rourke, who is trying to defeat Sen. Ted Cruz in Texas, said in July that he would not support Schumer. Rep. Kyrsten Sinema of Arizona also pledged to vote against the minority leader during her Senate race against Republican Martha McSally, as they vie to replace retiring GOP Sen. Jeff Flake.

Numerous Democratic candidates in competitive House races have also declined to support Nancy Pelosi for speaker if the party takes back the majority in the chamber, a scenario that's widely considered more like than Democrats swinging the Senate.

Early polls show Bredesen running close against Blackburn, but he will need healthy support from independents and Republicans to win in November. He is running to replace the retiring Sen. Bob Corker, a Republican who occasionally criticizes President Donald Trump. Corker has said he would not campaign against Bredesen, whom he considers a friend.

A Republican victory in Tennessee would cut off Democrats' path to a Senate majority unless they carry nearly all other competitive races on the map. The GOP currently holds a 51-49 majority and is targeting several Democratic incumbents running in red states.

A Bredesen win would mark a big reversal of fortune for the Democratic Party in Tennessee. No Democrat has won a statewide race in Tennessee since his successful re-election bid in the 2006 gubernatorial race, and the state has turned more Republican since then.

Bredesen has played down his party's chances of winning the Senate majority in the fall to potentially convince voters that his win would not hand power to national Democrats. He has also walked a careful line on Trump, who defeated Hillary Clinton by 26 percentage points in the state, by emphasizing that he is not running against the president.

Blackburn, his Republican rival and a stout Trump ally, dismissed Bredesen's vow to oppose Schumer.

"We know he will vote with Chuck Schumer because his vote is already bought and paid for, his campaign is bought and paid for by Chuck Schumer," Blackburn said. "I do think we all know that Phil had a choice. He could have run as a Republican or independent. Probably didn't want to do that. He's running as a Democrat so he will be with Chuck Schumer if he were to go to Washington."

A Schumer spokesman declined to comment.

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