Answer:
Because california is against the border of Mexico most immigrants travel to California.
When a person refers to a place as the backdoor of the country, it simply means that it is an easy way for aliens, or immigrants to gain illegal entry to a country.
With this in mind, California is close to the border of Mexico, so it would be justified into saying that it was a backdoor of the country as Mexicans without valid papers could easily evade detection by the immigration authorities and come into America.
Please note that your question is incomplete so I gave you a general overview which should be helpful.
Read more here:
https://brainly.com/question/22369398
