Beginning in 1914, Parr was elected to the Texas State Senate for numerous consecutive terms, serving nearly two decades, from 1915 to 1934.
Anglo in ancestry, Parr spoke Spanish and acted as a patron, developing a power base among the Mexican Americans who constituted the majority of residents in the county.
[citation needed] As a rancher, Parr learned Spanish and began to appreciate Mexican Americans as potential political supporters.
Parr treated his workers in the manner of a patron, helping the people and their families, giving favors and looking out for them.
[2] In 1908 Parr established his party, which he called El Guarache (sandal) (the poor), as opposed to La Bota (boot) (the rich, both Democrat and Republican.
)[citation needed] He built up his power among Mexican Americans and sometimes resorted to fraud and coercion to control elections.
Techniques included marked ballots, armed guards appointed by Parr who patrolled the polling places to intimidate voters, and alter election returns if needed.
In 1928 Parr and the Democratic Party tried to defeat Congressman Harry M. Wurzbach, the only Republican elected to Congress from Texas in this period.
He had won consecutive terms since 1920 from the 14th congressional district, which included Guadalupe County where German Americans had supported the Republican.
He had hoped that launching a road project with a quicker route to Corpus Christi, Texas, would help him win reelection.
His former friend and Democratic political ally, Congressman Richard M. Kleberg, opposed construction of the road across the ranch.