https://www.breitbart.com/border/2018/10/19/watch-migrant-caravan-tears-down-border-fence-storms-mexico/
I don't see any *signs* that said "USA or bust"
just some foreign blue-striped flag of some sort ... BUT THEY ARE STILL COMING THIS WAY STILL CARRYING THEIR FOREIGN FLAG ...
The flag of Honduras. They are flying the flag of Honduras. https://en.wikipedia.org/wiki/Flag_of_Honduras