He's all but said that he's running in TX-34.
Wherever he runs he loses
As currently drawn TX-34 is Biden+15. I don't think this is impossible given that the area seems to be trending right really hard and in landslides 1-2 seats like this usually fall (in 2014, Republicans picked up IL-10, which was Obama+17; in 2018, Democrats picked up NY-22, which was Trump+16), but even in an exorbitant landslide I expect most Biden+15 seats to not even be really vulnerable.
Also, usually the tendency is for successfully targeted reach seats to be seats trending away from you where you still have some downballot strength, and you can recruit good candidates and run a good campaign in a low-turnout midterm. TX-34 really doesn't fit that description -- it's incredibly, incredibly Democratic downballot!