AUSTIN, Texas -- Early voting starts Tuesday for the March 3 primary. It's finally a chance for Texans to weigh in on the presidential race. Another big one at the top of the ballot: U.S. Senate.

Twelve Democrats are vying for the chance to take on the presumptive nominee Sen. John Cornyn, R-Texas, in the fall. New numbers out Monday are giving Texans a little better picture of how that could shake out.

MJ Hegar has widened her lead over her rivals, according to the latest University of Texas/Texas Tribune poll. But all of the candidates remain strangers to a large majority of their primary voters. And a May runoff among such a crowded field is all but certain.

“It’s a sign that there’s something going on. They have a lot of interesting candidates, but nobody is a real frontrunner,” said James Henson, director of the Texas Politics Project at UT-Austin and co-director of the poll. “So that means that race is tied up until the end of May when there’s a runoff, in all likelihood, and the longer it takes to turn and actually take on John Cornyn, really the worse it is.”

Hegar, a decorated Air Force veteran, had the support of 22 percent of Democrats polled. Next was Austin activist Cristina Tzintzún Ramirez, at 9 percent, followed by former U.S. Rep. Chris Bell of Houston at 7 percent, and former at-large Houston City Council Member Amanda Edwards and state Sen. Royce West of Dallas each at 6 percent. Houston-area community organizer Sema Hernandez and Houston attorney and small-business owner Annie “Mamá” Garcia, each had 5 percent support. The other five candidates had two percent or less support.

Click the video link above to watch our full interview with Henson.