WASHINGTON -- Former Vice President Joe Biden and former Rep. Beto O'Rourke are in a dead heat among 2020 Democratic candidates in Texas, according to a poll released Monday.

In the Emerson College poll conducted April 25-28, Biden received 23% of support from Democratic primary voters while O’Rourke received 22%. The sample of Democratic voters has a margin error of 5.3 percentage points.

“It looks like Beto O’Rourke does not have Texas locked up,” Spencer Kimball, director of the Emerson Poll by Emerson College in Boston, said in a statement.

Sen. Bernie Sanders was the only other candidate in the poll topping 10%, polling third at 17%.

Mayor Pete Buttigieg of South Bend, Ind., received 8% and Sen. Elizabeth Warren of Massachusetts received 7%. Julián Castro, former Housing and Urban Development secretary and San Antonio mayor, polled at only 4% of support in his home state.

The Lone Star State could be an important battleground in this election and is vital now that it has moved up the calendar to Super Tuesday in early March.

The poll also found in a Donald Trump vs. Biden matchup, the two are almost even with Biden receiving 50% and 49% for Trump. O’Rourke and Trump are an even split with both candidates receiving 50%.

The survey also asked about a potential Senate race between newly announced Democrat MJ Hegar and longtime GOP Sen. John Cornyn.

Cornyn received 29% of support to Hegar’s 12%. There is still a long way to go in this race as 16% said they prefer someone else and 44% said they are unsure.

Hegar announced her bid last week, becoming the first major Democrat to launch a campaign against the three-term GOP incumbent.

She ran a surprise campaign last year against longtime GOP Rep. John Carter, earning widespread interest for a slick video advertisement about her life and coming within three percentage points of toppling the incumbent in a district Trump won by more than 12 percentage points in 2016.

Her announcement has shaken up the political landscape in the Lone Star State. After O’Rourke decided not to run for the Senate again in lieu of a presidential campaign, many assumed Rep. Joaquin Castro, D-San Antonio, would run after he decided not to in 2018.

That was a month ago and Castro still has not made a decision. He could make an announcement this week, the Texas Tribune reported.

The poll also asked about marijuana legalization and found that 38% support full legalization, 35% support marijuana use for medical purposes only, 13% would like it decriminalized and 14% said it should remain illegal.