'65 Dart No brake lights. Brake light switch failure?

Wouldn’t the turn signal switch failure make the turn signals not work? The turn lights are working and there is voltage to the brake light switch.
No this is a common failure. The TS switch can fail and the signals still work but not brake lights. In the 70/ and later cars, this is commonly caused by the integrated hazard switch

Check the "output" of the brake light switch. I believe this is the white at the column TS switch connector. If you have brake light power there, of course pedal depressed, then it's the TS switch

Try working the hazard switch a few times