Are they going to close the state border to prevent such contraband from coming in?
Checkpoints.
A car full of Illegals approach:
Border agent with purple hair and nose ring: Drive on thru and Bienvenidos to Californiastan! Be sure to fill out your mail-in ballots for harvesting later, hombres!
Everyone else pulls up:
Border agent: You got any fruits, vegetables, banned small gas engines? Did you vote Trump? Like guns, think there’s only two sexes. Turn around and go back, MAGAt!!!
“Are they going to close the state border to prevent such contraband from coming in?”
I’m certain your question is rhetorical, but I assure you, they monitor their interior U.S. border more than you might think.
A friend of mine was traveling to CA from TX on business and drove so he could enjoy the scenery of the Southwest. Upon entering California he was pulled over and the cops surveyed the inside of his vehicle and made him surrender some fruit he had with him, bananas and oranges I think.
He could NOT bring them into the state. This was 5+ years ago.