Texas Polling Area DensitiesThe trends in polling densities seem to indicate the center of population for Texas respondents is in the central polling area. Perhaps the spread of 42 into this area was influenced by the railways in the late 1800s (before cars and highways).
Prior to the reported origin of 42 in Garner in 1887, there were railways in many areas of Texas. One needs only to examine the early rail routes in Texas (1874) to speculate how the game of 42 made its way to Travis, Lee, Kerr, Brazos and other Texas counties.
Since domino games were popular among European immigrants, it seems plausible that 42 might have spread more extensively in the central polling area after its introduction there. (Or maybe 42 is largely a rural game, and large population centers like Dallas, Houston, and San Antonio tend to dilute the densities in those polling areas.)
Assuming 42 originated in Garner, the polling results indicate the game also migrated in a southwesterly direction, to the central polling area where the highest density of 42 respondents currently reside.