Reading more about DNC chair elections, the state party’s vice chair usually also votes for chair too (among others). For Texas, that’s Shay Wyrick-Cathey ([email protected])
For what it’s worth it looks like his comments about trans people are what produced a large push to get the Texas Democratic party chair to step down. He said he was stepping down the day after he gave an apology
If you’re a US citizen living abroad, there’s the Democrats Abroad party chair to reach out to, there are also various US territory chairs too (Puerto Rico, U.S. Virgin Islands, DC, etc.)