In order to vote, you must be registered. Applications must be submitted at least 30 days before the election date.
In Texas, citizens do not register by political party, but simply register in their county of current residence.
You may Register to Vote during the Round Rock Dems Meetings, request to do so upon arrival. WilCo Volunteer Deputy Voter Registrars are routinely in attendance.
Remember you need an approved picture ID to vote in TX.
Further Voting Information: Voting Center Locations, Acceptable Picture Identification. Polling Hours: http://www.wilco.org/Departments/Elections