Could you stick a jack dempsey and a Texas cichild in a 50 gallon tank?

you could probably get by with it but if you are going with a blue Texas cichlid and a jack dempsey cichlid in the same tank there will be some rivalry because they look very similar. (jacks don't like fish that look like them)

i don't know much about Texas cichlids, if they are territorial you want to go with a bigger tank. Jacks are VERY territorial and will kill anything to claim its fishtank.

Hope this helps! :]

by the way, both cichlids prefer 55 U.S. Gal + you could get by with them together, make sure that the jack is smaller also otherwise if its bigger it might kill your Texas cichlid.