I don't think the Democratic Party will have huge majority among latinos forever.
In the future, white latinos may be only white. That's what happened with other non-Anglo Saxon white groups.
Latinos running away from poverty in Latin America are usually Democratic. But Cuban Americans are Republican. They were rich citizens running away from Castro regime. Nowadays, there are many rich citizens from other Latin American countries moving to the USA running away from the elected center-left governments. They are like cuban immigrants. When they become American citizens, many of them will probably vote Republican.
I saw a story how the US in 2050 will filled with whites who have hispanic last names. Intermarriage will dilute hispanic identity and loyalty to the Dem party. The Dems need racial and ethnic hatred.