FRISCO, Texas — Six of the seven Democratic candidates running for U.S. Senate will meet in Frisco Thursday afternoon for the first major event of the state’s primary.

"Frisco was first for a reason. The suburbs will decide the 2020 elections. Places like Denton County & Collin County could be the reason Texas turns blue,” said Ira Bershad, president of the Frisco Democratic Club, who organized the United States Senate Candidate Forum.

Former Congressman Chris Bell, Houston Councilwoman Amanda Edwards, Sema Hernandez, Adrian Ocegueda, Cristina Tzintzun Ramirez, and state Senator Royce West will attend the forum sponsored by the Frisco Democratic Club.

M.J. Hegar’s campaign said she had a previous commitment and could not participate today.

WATCH the full debate

One of the Democrats will face incumbent John Cornyn in the 2020 presidential election. Despite more than 30 years of public service, Cornyn’s approval rating is mediocre with the same number of Texans disapproving of him than approving.

The United States Senate Candidate Forum happens at 12:30 p.m. at Collin College’s Preston Ridge Campus.

WFAA’s Jason Whitely, host of Inside Texas Politics, will moderate the forum.

The suburbs will likely be decisive in the 2020 presidential election. Long a Republican stronghold, the GOP has seen its support their erode in the last couple election cycles.

On Wednesday, The Hill named Tarrant County as a bellwether for the 2020 presidential election. The website said Tarrant County is one of ten counties nationwide that could determine the next president. Tarrant has traditionally voted Republican but in 2018, flipped to Democrats narrowly.

More on WFAA: