The chart above is from the Morning Consult Poll. They questioned 2,576 likely voters in Texas between July 24th and August 2nd, and their survey had a 2 point margin of error.
The poll showed Joe Biden with a 1 point lead over Donald Trump (47% to 46%). That means the two are virtually tied in the state right now. This is why Biden recently beefed up his number of campaign workers in Texas.