The election will be determined before July 1.
The election will be determined when the assaulting army tries to force the border and is repelled by American action not only against the invaders but the Mexican government sovereignty. When the invaders reach the border, Trump will challenge and destroy Mexican sovereignty
The Mexican Government existence is dependent on controlling the invasion
The US Government existence is dependent on controlling the invasion.
Trump (and US) is finished if he lets them in.
So who’ll be in charge of a failed Mexican state? Does anyone really want that grief?