NASHVILLE (AP) — Former Tennessee Democratic Gov. Phil Bredesen and Republican U.S. Rep. Marsha Blackburn are on a collision course to claim their own slices of history in a critical U.S. Senate race.

Blackburn, an ally of President Donald Trump, would break ground as the first woman Tennessee ever elected to the Senate.

Bredesen could breathe life into a depleted Democratic Party in Tennessee that hasn't won statewide in more than a decade — not since he did it himself in his 2006 re-election bid. It's been even longer for Tennessee Democrats to see success in Senate races. The last to win was former Vice President Al Gore in 1990.

Tennessee voted for Trump by 26 percentage points in 2016, but Bredesen's continued popularity and pledge of independent thinking have kept polls close in the contest to replace retiring Republican Sen. Bob Corker. The race could run up a record spending tab as Democrats hope to anchor their fight to steal the 51-49 Republican Senate majority on the red, southern state.

Blackburn and Bredesen have long run their race like their matchup was inevitable. Easy primary wins Thursday just made it official.

The Bredesen playbook has come into play in an open governor's race as well, where Democratic former Nashville Mayor Karl Dean has touted himself as a leader who can break down partisan barriers and work with a Republican legislature during divisive political times. He easily won a primary contest Thursday.

Dean faces businessman Bill Lee, who emerged from a bruising, $45 million-plus Republican primary as the race's only self-described "conservative outsider" and the candidate who most emphasized his Christian beliefs. The four leading candidates tapped into an unprecedented $40 million of their personal wealth.

The Democratic nominee from Franklin tried to avoid the fray and the $7 million he spent was a third of that of Randy Boyd, the second-place finisher. Lee declined to take overt swipes at his opponents while they savaged each other in attack ads, at times targeting him.

The race also included U.S. Rep. Diane Black, who began the campaign as the favorite and got the endorsement of Vice President Mike Pence but stumbled to a third-place finish.

In the Senate race, Bredesen is pledging to work across party lines, saying he will support Trump on policies that are good for the state, and oppose him when they aren't.

He thanked his supporters Thursday night and vowed to be "the best damn senator you ever sent up to Washington."

Blackburn has run in support of Trump's agenda, including his wall-building immigration crackdown and his U.S. Supreme Court pick, Brett Kavanaugh.

"We know what Tennesseans say that they want to see in their next senator is somebody who is going to stand with President Trump to finish the agenda that they voted for when they elected him and sent him to Washington," she told her supporters, some of whom were wearing "Marsha Marsha Marsha" T-shirts.

Bredesen and Dean would need to peel off support from moderate Republicans and independents in the red state.

Blackburn has billed herself as a "hardcore, card-carrying Tennessee conservative" from the outset of her campaign. She has benefited from center-stage appearances alongside Trump and Vice President Mike Pence in public events and fundraisers in Tennessee.

Pence and Trump have already attacked Bredesen, saying he's too liberal for Tennessee and would fall in line with Democratic Minority Leader Chuck Schumer.

Bredesen has countered that his record as governor shows he's an independent thinker who won't cave to party leaders.

Bredesen has separated himself from Trump on several policies, most notably on tariffs, which threaten an estimated $1.4 billion in Tennessee exports, according to the U.S. Chamber of Commerce, a longtime Republican ally. The exports are linked to more than 850,000 jobs in the state related to farming, steel, baked goods, car manufacturing, whiskey distillers like Jack Daniel's, and more, the chamber said.

Blackburn has tried to distance herself from the White House carefully on tariffs amid a heightening trade war. She asked the commerce secretary to reconsider broad tariffs to avoid harm to Tennessee's economy. She has expressed "grave concern" about the tariffs, but said she appreciates the administration's goal of punishing bad actors like China.

Blackburn has opposed Corker's proposal to require a congressional vote on tariffs issued in the name of national security, a move that fellow Tennessee GOP Sen. Lamar Alexander supports.

Tennessee has a history of electing centrist senators. Corker, for one, has further complicated the race by saying he's supporting Blackburn but won't actively campaign against Bredesen, whom he has called a friend.

Corker also has publicly tussled with Trump, once saying the president had turned the White House into an "adult day care center." Trump tweeted in response that Corker "couldn't get elected dog catcher in Tennessee," and Corker endured booing at a Trump-Blackburn rally in Nashville this spring.

Haslam, the popular two-term governor, threw his support behind Blackburn at a campaign event Thursday, telling her supporters that the race is about control of the Senate.

Heading into July, Blackburn maintained an early 2-to-1 cash advantage over Bredesen, with $7.3 million in her bank account. But Bredesen would be one of the wealthiest members of Congress if elected, and he has already loaned $3.5 million of his own money to his campaign.

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Sheila Burke in Nashville contributed to this report.