agree on infrastructure needs. states manage most infrastructure, but feds do contribute some funds. taxpayers pay billions of dollars in infrastructure taxes. in my state, we pay about .35/gal of fuel, plus additional measures passed over the years that add percentages to sales taxes. the problem is the funds get rerouted to other things. a current example for me is this stupid train gov brown wants to build in CA. they want to take over $650M collected for road improvements to use for their train instead. thats not how they got that money!! the money is there, but politicians want to spend it elsewhere.
just like we pay for things with a tax, mexico will pay for the wall...via tax. trade war? unlikely. mexico needs us more than the we need them, so they'll come around because they will have to.
you/we here in the US, are on the winning team. the rest of the world is doing the same as us; getting theirs the best they can.