Which of these migrations have had the greatest impact on the current political landscape of the State of Texas?Why?

The last century has seen three significant migrations that have directly affected Texas: The Great Depression, the Northern Migration from Central and South America, and the Southern Migration from the Midwest, as well as from California and New York. Given the historical context of Texas’ political development, which of these migrations have had the greatest impact on the current political landscape of the State of Texas?Why?

Some possible sources to consider include:

Johnston Ron, Fred M. Shelley and Peter Taylor, eds.. Developments in Electoral Geography (Routledge Library Editions: Political Geography) Vol.7. Routledge, 2014

Lind, Michael. Made in Texas: George W. Bush and the southern takeover of American politics. Basic Books, 2009.

McKee, Seth C. and Daron R. Shaw. “Redistricting in Texas: Institutionalizing Republican Ascendancy.” 2005