Why do some Mexicans hate Americans so much?

Wildwood - Why do some Mexicans hate Americans so much? Some attack many U.S. citizens; black, white and Latino at peaceful Trump rallies. Some attack our police and damage properties. Some called it racist and protested when American students wore the American flag at an American school on Cinco de Mayo. Some burn the American flag while waving the Mexican flag. Some think they have the right to come here illegally while millions wait in line to come here legally. Americans would never get away with doing those things in Mexico and you better have proof that you are in Mexico legally.