Tennessee’s candidates for the U.S. Senate -- Republican U.S. Rep. Marsha Blackburn and Democratic former Gov. Phil Bredesen -- will hold a final debate at 8 p.m. tonight at the University of Tennessee’s Howard H. Baker Jr. Center for Public Policy.

A final showdown,
with Trump and Taylor
tangling in the wings.

The public will not be permitted in the small Toyota Auditorium, where the candidates will answer questions on the issues, but the debate will be livestreamed in Alumni Memorial Hall’s Cox Auditorium and broadcast locally on WATE-TV, Channel 6, and WUOT, 91.9 FM.

Blackburn has aligned herself with President Donald Trump while attempting to portray Bredesen as beholden to Senate Minority Leader Chuck Schumer. Bredesen has run as a bipartisan pragmatist, and last week he stunned his fellow Democrats by endorsing the controversial confirmation of Justice Brett Kavanaugh to the U.S. Supreme Court.

Singer Taylor Swift added some star power to the race this week by taking to Instagram to criticize Blackburn and endorse Bredesen, along with the Nashville Democrat Jim Cooper, who is running for re-election to his House seat. By weighing in on the races, Swift broke a longstanding silence on political matters.

"In the past I've been reluctant to publicly voice my political opinions, but due to several events in my life and in the world in the past two years, I feel very differently about that now," Swift said in her post on Sunday.

After learning of Swift’s endorsement of Bredesen from reporters on Monday, President Donald Trump said he liked the pop star’s music “about 25 percent less.” (Billboard helpfully rounded up everything Trump has ever said about Swift.)

A recent CBS News poll showed Blackburn with an 8-point lead, though polling ended one day before Bredesen announced his support of Kavanaugh’s nomination. Previous polls have indicated a much closer race.

Swift also urged her Instagram followers to register to vote. Her views on Bredesen might or might not affect the Tennessee Senate race, but the voter registration website Vote.org says it’s had a profound effect on registrations.

“We have never seen a 24- or 36- or 48-hour period like this,” Vote.org spokeswoman Kamari Guthrie told the New York Times on Tuesday.

Forty-two percent of the 166,000 people submitting new registrations through Vote.org between Sunday and noon on Tuesday were between the ages of 18 to 24, officials told the Times. Tuesday was the last day to register to vote in Tennessee and many other states.

Somewhat less surprising than the Swift endorsement was Knoxville Mayor Madeline Rogero's announcement Tuesday that she is also supporting Bredesen.