I was part of a successful write in campaign for congress in 1980 when Joe Skeen won.
No write-ins in primaries in TX and maybe anywhere. Only in general elections. The NM election won by Skeen was a general election, not a primary. Many people would not understand how to write in a candidate; in TX the write-in candidate must be a “declared” candidate. One can’t write in his own name and expect it to be counted.
That must have been exciting! That’s the race where the recently deceased Democrat incumbent’s widow ran as a write-in as well, right?