Eligible Texas voters who have not done so already have until April 7 to register to vote in the May 7 statewide constitutional amendment election, as well as any local elections for city, school districts and other local entities.Both propositions deal with property taxes. The first reduces the total amount of property tax imposed on elderly or disabled persons. The second increases the homestead exemption on school taxes from $25,000 to $40,000.Early voting begins on April 25 and runs through May 3.Texans also will have the opportunity to return to the polls on May 24 for the primary runoff election.