Trump leads polling in TX, a state where polls traditionally underestimates Ds (not saying it won;t this cycle, but no "muh 2016" argument. Also, I still think Hegar is an underdog, but undecides look really ripe for her.
I really believed that Hegar was only trailing Biden in polls due to very low name ID and that she'd ultimately was going to run incredibly close to Biden and could possibly ride that to a win, but in the couple of crosstabs I've seen of "already voted" in TX, there clearly seems to be an more meaningful Cornyn/Biden crossover vote than I'd thought. Unless something happens to really blow the race further open in the next few weeks and she gets a boost in late early voting/Election Day, I'm starting to think her goose is cooked even if Biden wins TX.