I've got some ideas for a historical twist in demographics:
After the abolition of slavery in the British Empire in 1833 IOTL, the British imported Indian indentured servants to the Caribbean, Guyana, Fiji and South Africa, and today Trinidad/Tobago, Guyana and Suriname (which was Dutch) are majority Indian, with other places like Jamaica having Indian minorities. In fact, between 1838 and 1917, over 500,000 Indians were imported. It's possible that when the British abolish slavery ITTL (probably later than IOTL, since there'd be millions more slaves to compensate for the slave owners) that many Indians would be imported to the Deep South to work on the plantations, since the African-Americans are no longer slaves.
Another divergence might be the British importing Asians such as Chinese, Japanese and Filipinos to the west coast for agriculture. The U.S. IOTL brought a lot of Japanese, Koreans and Filipinos to Hawaii, which is why Hawaii is the only Majority-Asian state in the U.S. today. I could see agriculture in California's Central Valley using lots of Asian labor, especially for crops like rice, which is the main crop in East Asia and is a crop grown in OTL California (and also in parts of the Deep South). Today, the West Coast could have a larger Asian population, especially in the Central Valley of California and in irrigated areas such as the Colorado River valley.
So, what do you guys think? Is this plausible?