Why is America still the dream for thousands of Haitian (and other) migrants?

I find it hard to fathom the mindset of the thousands of Haitians (and Venezuelans and other nationalities, but mainly Haitians) who make the perilous journey to Colombia, through the roadless jungles of the Darien Gap into Panama, and then across the borders of a bunch of other Central American countries to Mexico and ultimately to the southern border of the United States of America. Nearly 4,000 kilometres on foot through hostile and dangerous territory, crossing around 80 rivers and at least two sections of open sea, all to get to the so-called Land of the Free ... which has said (and shown) repeatedly that they are not welcome.

Thousands have already been deported right back to Haiti from the Mexico-US border, after all that inconceivable hardship, injury and, yes, loss of life. Some get side-tracked along the route, sometimes spending years in South American countries like Chile, Brazil or Peru. But the USA is always the dream, the ultimate destination, even though it is no easier to get in now than it was under Donald Trump. A few are slowly starting to reassess those dreams, and considering halting in Mexico.

But surely they must know that their chances of getting into the USA are slim to nil and that, even if they do, they will be forever on the run, evading authorities, and living a liminal existence at best. What is the attraction of America in this day and age? is it just the promise of more money (even under the counter, in semi-slavery conditions), because the US is a richer country? Can that really be enough to risk so much, and to put up with so much hardship? 

I know that things in Haiti are grim, and that these are desperate people. But I still find it quite literally impossible to understand their frame of mind