Nope. Only an independent may run as a write in in Texas. A person who has chosen to affiliate with a political party for the two year election cycle, may not. White affiliated with the Republican Party for this cycle by filing for a place on the ballot, in Texas House District 19, as a Republican:
http://www.texasgop.org/elections/candidates/
White might been able to unaffiliate if he had had time to withdraw his application for a place on the ballot. But if he had had time to do that, he could have just filed for Texas 36 in Congress.
Good point, because he is running for reelection to Austin, he can’t run this year for a chance in DC. Are any of the Dist. 36 Republicans acceptable?