Not really. The Mexican government used to let them pass through, for political propaganda purposes - but of course DID NOT let them stay in Mexico. However it appears that even Mexico has had a wake up call and now it doesn’t sound like they’re going to permit even this.
I don’t think it’s Trump’s money threat that’s causing this, but the fact is that Trump has given Mexican pols the courage to stand up to this manipulation. So we shall see. The new president of Mexico is a raving leftist, but at the same time pragmatic, and Trump is also pragmatic.
Mexico has DECLARED WAR on the United States.