The study examined the hypothesis that Mexican Americans in south Texas were not holders of certain county offices in proportion to their population in the selected counties, utilizing adjusted population counts (i.e., persons aged 18 years and over or those who were potential voters and/or officeholders). Twenty-eight counties were chosen on the basis that they were situated in south Texas and had at least 40 percent Mexican American constituency. The offices consisted of county judge, attorney, auditor, clerk, treasurer, assessor, sheriff, commissioners, and justice of the peace. These offices were usually filled by election. Between September and December 1975, a short questionnaire was mailed to county clerks, requesting information on: names of officeholders, whether the office was elective or appointive, and ethnicity and sex of officeholder. After the first mailing or the follow-up, responses were obtained from all but two counties. Data were obtained from the "Texas Almanac" and chambers of commerce for the remaining two. Some findings were: on a county-by-county basis, Mexican Americans were underrepresented in 20 of the 28 counties--in 9 of the 20 counties, Mexican Americans held more than 50 percent of the offices; and the post of auditor was the only one not predominantly elective and the one in which Mexican Americans held the lowest number of positions. (NQ)