As Tennessee’s Senate race continues to heat up, tomorrow’s primary elections will solidify which two candidates will face each other in November.

Representative Marsha Blackburn leads the GOP field vying for the seat being vacated by retiring Senator Bob Corker, also a Republican. She has been endorsed by President Donald Trump, who traveled to Tennessee in May to campaign for her.

As for the Democrats, former governor Phil Bredesen has emerged as his party’s leader. He leads Blackburn by less than 5 points, according to Real Clear Politics’ polling average.

This Senate race is considered a toss-up by Fox News. It is among several races crucial to Trump’s plans to maintain control of the Senate, where Republicans are defending a narrow two-seat majority.

Trump won Tennessee with more than 60 percent of the vote in the 2016 presidential election.