Why did Zapata County, TX swing so hard from R to D in the 1920s?

[CadetCashBoi]

Zapata County, TX gave William Howard Taft 100% of the vote in 1912 and was one of Charles Evans Hughes best counties in 1916 and gave Harding a slightly reduced majority before swinging hard to John W Davis. Why is this? One of the more bizarre electoral histories I've seen.

[seeking mystical annihilation]

This is the case for multiple South Texas counties that were controlled by Republican bosses before Democratic machines took over. Another rural Southern county (equivalent) with such a corrupt top-down system is Plaquemines Parish, LA, whose control by arch-segregationist apparatchik Leander Perez speaks for itself in the Presidential topline.

[falling apart like the ashes of American flags]

Zapata County, TX gave William Howard Taft 100% of the vote in 1912 and was one of Charles Evans Hughes best counties in 1916 and gave Harding a slightly reduced majority before swinging hard to John W Davis. Why is this? One of the more bizarre electoral histories I've seen.

Elections in that part of Texas at the time were significantly less free and fair than modern day elections in Russia.